Mrs. Dashwood and her daughters are left to the will of her step-son, John, and his wife after her husband dies. Her step-son's wife does not like Mrs. Dashwood and her daughters, so it is determined they should move out of their home as soon as possible. Currently they are sharing their home with John and his wife, who are the legal owners of the home.

The oldest daughter, Elinor, is in love with John's brother-in-law, Edward. They are moving to Barton Cottage, which is owned by Sir John Middleton. There they meet Colonel Brandon and Mrs. Jennings, who is Lady Middleton's mother and through an accident meet Mr. Willoughby.

Willoughby, who rescues Marianne after she falls spraining her ankle, falls in love with her. This leads Elinor to wonder if they are engaged and if so, why have they not publicly announced it.

Meanwhile, Colonel Brandon has shown great interest in Marianne, but realizes she is not interested in him. Edward comes to visit Elinor, but he seems cold and distant towards her.

One day Willoughby tells Marianne he must leave for London on business for his relative, who is also the person he hopes to inherit from one day. She is greatly upset, but hopes to see him soon.

Edward is depressed, because he cannot find an occupation which will suit both himself and his mother. One night Marianne sees Edward wearing a ring with a lock of hair in it. He tells her it is his sister's hair, but Elinor thinks it might be hers, as she hopes they will marry one day.

Mrs. Jennings brings two young ladies to visit at her daughter's home, they are the Steele sisters, Anne and Lucy. Lucy confides to Elinor that she and Edward have been engaged for four years and the lock of hair is hers, this news staggers Elinor.

While dealing with the news of Edward's engagement, Elinor and Marianne are asked by Mrs. Jennings to live with her in London for a while. It is decided they will go, making Marianne happy, because she thinks she will see Willoughby there.

Marianne waits for Willoughby to visit her in London, but he never does. Instead, one night at a party she sees him with another woman. Willoughby tries to ignore Marianne, but she will not be ignored and demands his attention. Marianne is devastated by his behavior towards her and asks to leave immediately.

Marianne wallows in her grief, after seeing Willoughby the night before. Elinor is visited by Colonel Brandon, who tells her that Willoughby has fathered a child, with a girl who is under Colonel Brandon's guardianship. He also informs her Willoughby left the girl to fend for herself. It is found out that Willoughby is engaged to Miss Grey.

In early February the news of Willoughby's marriage is received by the sisters, which causes Marianne to be upset again. Also, the Steele sisters come to London, which gives Lucy the chance to flaunt her engagement to Elinor again.

Elinor and Marianne see their half-brother John and he visits them at Mrs. Jennings's home. There he meets Mrs. Jennings and Colonel Brandon; who John thinks is in love with Elinor. Later he meets the Middletons, for who John and his wife give a party, which includes the Steele sisters and Mrs. Ferrars, Edward's mother. Mrs. Ferrars likes Lucy, as she doesn't know about the engagement, because the family thinks Edward is getting engaged to Miss Morton. John decides he wants to ask his sisters to stay with him, but his wife would prefer to have the Steele sisters stay.

While staying with John Dashwood and his wife, Anne Steele tells Mrs. John Dashwood of Lucy's engagement to Edward, who is Mrs. Dashwood's brother. She does not take the news well and insists the sisters leave as soon as possible.

She tells her mother what has happened, which causes Mrs. Ferrars to give Edward an ultimatum of either ending the engagement or being cut off financially and personally from the family. He chooses Lucy and the two of them decide to wait till he is ordained as a minister to marry. Colonel Brandon offers Edward a living at Delaford, which he accepts.

The two sister agree to go to Cleveland, the home of Mrs. Jennings's other daughter. While at Cleveland, Marianne becomes ill and almost dies. Colonel Brandon brings Mrs. Dashwood to her daughter.

While Elinor is waiting for her mother, Willoughby comes to the house, to tell her the reason he left Marianne; he was disinherited by his relative and thrown out of her home. He wants Marianne to know he is sorry for his actions.

Marianne begins to recover from her illness before her mother arrives. Mrs. Dashwood tells Elinor Colonel Brandon confessed his love of Marianne to her.

After Marianne recovers from her illness, the ladies return to Barton Cottage. One day they are visited by Edward Ferrars, who tells them Lucy married his brother, Robert. He proposes to Elinor and after being returned to the good graces of his mother, they are married.

Marianne and Colonel Brandon become closer and eventually marry also. Willoughby finds some happiness with his wife and his relative gives him back his inheritance. Mrs. Dashwood remains at Barton Cottage with her youngest daughter, but she visits her other daughters frequently.

The book shows how young people can sometimes make unwise decisions, but with the help of their families can turn them into good situations. The characters of the book are trying to be sensible in their actions and to conform to the social expectations of their times. These are not always easy objectives to achieve, no matter how well intentioned those involved efforts are.