The factor structure and reliability of the Female Sexual Function Index (FSFI) was evaluated in a Finnish population based sample of 2,081 women, age 33-43 years. In addition, associations between female sexual function and age, psychological distress, alcohol use, hormone based contraceptives, child sexual abuse (CSA), and adult sexual abuse were examined. The results supported a six factor solution for the FSFI with high internal consistencies, in line with earlier research in clinical populations. Psychological distress was positively associated with every dimension of the FSFI except desire problems. Age was associated with fewer pain problems. Alcohol use was associated with every dimension of the FSFI, but the direction of the association depended on if it was drinking in general or in connection to intercourse. More drinking in general was related to fewer sexual function problems while drinking in connection to intercourse was related to more sexual function problems. No significant correlation was found between adult sexual abuse and sexual function but between CSA and lubrication, satisfaction, and pain problems. Usage of oral contraceptive pill was not significantly associated with sexual function. The use of hormone based intrauterine systems was significantly associated with less pain and more desire, arousal, and satisfaction. In conclusion, the study supports use of the FSFI for assessing sexual function not only in clinical samples but also in population based samples. The associations found between sexual function and other important variables showed the complexity of sexual function.