Childhood sexual abuse (CSA) has been associated with increased risk for alcohol dependence (AD), but the extent to which CSA history may impact transitions in the course of AD development remains unclear. The current study examined the role of CSA in initiation of alcohol use and rate of progression from first drink to AD using a sample of 3536 female twins (mean age=21.6 years). Psychiatric diagnoses and alcohol use histories were obtained via telephone interviews using an adaptation of the SSAGA. The contribution of CSA to alcohol outcomes independent of familial influences was estimated by using co-twin AD status to adjust for familial liability to AD. CSA was associated with higher rates of both lifetime alcohol use and AD, but CSA-associated risk for consumption of first alcoholic drink was evident only at ages 12 and 13. Rate of transition from first alcohol use to AD did not differ by CSA status. Findings indicate that CSA and elevated risk for AD may be linked via early age at first drink and that progression from first drink to AD follows a similar course among women with and without histories of CSA.