The show focuses on the issue of teen pregnancy.

Amy Juergens is a 15 year old girl who slept with Ricky Underwood one night at band camp. Amy finds out she is pregnant and tries to keep it from her parents. She meets a boy named Ben Boykewich, who's father is the sausage king, at school and he asks her to a school dance. He falls in love with her. Later he finds out that she is pregnant with Ricky's baby but doesn't care. He wants to marry her and raise the baby as if it is his own. At first Ricky didn't want anything to do with the baby but by the end of the second season he starts having feelings for Amy and wants to be with her and the baby. At first Amy had no plans to keep the baby because she doesn't believe that she can take care of the baby. After her friends, Ben, and Ricky help her out and will be there for her once the baby is born she decides to keep the baby. She says that with the help of everyone she will be able to take care of the baby.

Grace Bowman is a Catholic who believes in saving herself until after marriage. She meets Jack Pappas and falls in love with him. She believed that he was the one for her. She finds out that he kissed and slept with Adrian so she breaks up with him.

Adrian Lee is the type of girl who would sleep with anyone. Her mother is a flight attendant so she is home alone most of the time. One day she went in search of her biological father and finds him. Her biological father is married to a woman who has a son. Andrian ends up sleeping with him. She finds out he is in love with her but she's not in love with him.

Ricky lives with foster parents. His father is a drug seller/user and has been in and out of jail. Ricky was abused by his father. At first he wasn't sure if he would be a good father to the baby because of his father. Ricky believed that he might abuse the baby like his father abused him.