The main theme of the book Ethan Frome is failure. It is shown in three ways throughout the story: Ethan's marriage, him not being able to stand up to Zeena, and his involvement in the "smash up".

Ethan marries Zeena so he won't be alone after his mother dies. She seemed like a very cheerful, vivacious person while his mother was sick. After their marriage all this changed. She became a very nagging, sick wife. Because of Zeena's "complications" they had to hire someone to help around the house. Mattie, Zeena's cousin, needed a place to live and seemed fit for the job. She moved in and Ethan took and immediate liking to her. He found someone that cared for him, was always happy, and could share his youth. All of which, Zeena was incapable of doing. Ethan longed to be with Mattie, but he was loyal to Zeena. Being married to Zeena was Ethan's first failure.

Ethan's second failure was not standing up to Zeena. She claimed the doctor said that she was extremely sick and needed more help around the house. She told him without any discussion that Mattie had to go. Ethan could not find the words to make her alter her decision. Zeena also decided that Mattie had to leave the next day. It was stated in the book that Zeena had the upper hand in the house by the line "Now she [Zeena] had mastered him [Ethan] and he obeyed her." Ethan could not find the right things to say, and it was because of his failure of not being able to stand up to his wife that he was going to lose the only thing that made him happy.

Ethan's last failure was the way he modified his and Mattie's lives regarding the "smash up". He wanted to run away with Mattie, but he could not because his practical sense told him it was not feasible to do so. Mattie wanted so desperately to be with Ethan that she suggested in order to stay together forever, to die together. It was Ethan's job to steer into the tree with the sled so that it looked like an accidental death. He did not hit the tree right and it did not kill either of them. Instead it injured them, and these injuries stayed with them forever. In this way, Ethan had his last failure in not exceeding to die with his love. Now he had to live with the guilt from his wife, the injured Mattie, and broken dreams. Everything Ethan tried to do worked against his favor. With all the incidents that happened it seemed inevitable that his life would always be a string of failure.