A cancer diagnosis can motivate people to modify behaviors believed to influence prognosis or recurrence risk, including their eating habits. Orthorexia is a type of disordered eating that involves an extreme fixation on healthy eating. The current study examined: 1) the presence of orthorexia symptoms and disordered eating behavior in young adult women with cancer; 2) factors associated with orthorexia and disordered eating behaviors; and 3) the type and frequency of eating behavior changes made following cancer diagnosis.