Women with a history of childhood sexual abuse (CSA) are at greater risk for experiencing sexual problems in their adult lives. Yet, little is known about the possible role of cognitive and affective mechanisms in the development of sexual arousal difficulties in this population. This study investigated the role of pre-existing affect (affect prior to exposure to sexual stimuli) on genital responses, subjective sexual arousal, and affect elicited during the presentation of erotic film excerpts in a community sample of 25 women with and 25 women without a history of CSA. The CSA group showed greater pre-existing negative affect and smaller genital responses to the erotic film stimuli compared to the NSA group. Findings support a moderating effect of CSA, in that pre-existing negative affect was associated with strength of genital responses in the NSA but not in the CSA group. The results did not support a mediation model of pre-existing negative affect as an explanation for smaller physiological sexual responses in the CSA group. Taken together, the findings suggest that pre-existing affect may be more relevant for women with no history of CSA and call for more research on factors implicated in impaired sexual responses in women with a history of CSA.