Data suggest that individuals dealing with a cancer diagnosis are less likely to suffer from depression, anxiety, and psychological distress when they cope with their condition from a stance of emotional and cognitive acceptance (e.g. Dunkel, et al., 1992; Stanton, et al., 2000). Although traditional CBT often includes some acceptance-oriented elements, recent variants of CBT, such as Acceptance and Commitment Therapy (ACT), have acceptance as a central focus. ACT targets emotional distress directly through acceptance of difficult thoughts and emotions. The current study is a preliminary comparison of ACT and treatment as usual (TAU) in the treatment of emotional distress among women with late-stage ovarian cancer. Forty-seven women diagnosed with Stage III or IV ovarian cancer were randomly assigned to one of two treatment conditions. Treatment consisted of 12 face-to-face meetings with a therapist, each following a TAU or ACT protocol. Results indicate that both groups showed improved mood and quality of life following the intervention. The ACT group showed significantly greater improvements compared to the TAU group. Furthermore, mediation analyses indicate that the effects of treatment were mediated by cognitive avoidance. Although the study is limited by the implementation of treatment in both conditions by a single therapist, the TAU group showed improvements that were consistent with effect sizes available in the literature, suggesting that the intervention was a credible and effective control treatment. These findings provide preliminary support for the use of ACT in ovarian cancer populations. Further work is needed to investigate the effectiveness in other oncology populations as well as investigate potential patient characteristics which may interact with these interventions.