BackgroundLittle is known about the occurrence and health consequences of intimate partner sexual assault. The aim of this study was to assess the prevalence and correlates of sexual assault in the context of intimate partner violence (IPV) in Thailand.MethodsIn a cross-sectional survey adult female participants were systematically screened (self-administered or interview administered) for IPV in antenatal care and general outpatient clinics in nine randomly selected hospitals in two provinces in the central region. Measures included the Abuse Assessment Screen, Severity of Violence Against Women Scale, Danger assessment and suicidal behaviour.ResultsFrom 14,288 women screened, 1.5% were positive for IPV and 207 participated in the study. The mean age of the study participants was 26.8 years (SD = 9.3). Fifty-seven women, 27.5% of the sample, reported sexual assault, one or more times, during the relationship in the past 12 months. Most reported some form of psychological abuse (82.1%), physical violence (67.1%) and danger (72.0%). In all, 21.3% reported psychological, physical and sexual violence. Bivariate analyses found that older age, being recruited in the general out-patient department, greater number of children, high psychological abuse, high physical violence, danger and suicidal behaviour in the past 12 months were associated with sexual assault. In multivariable backward conditional logistic regression physical violence (OR = 5.32, CI = 2.52–11.24) and suicidal behaviour (OR = 3.28, CI = 1.37–7.83) were found to be associated with sexual assault.ConclusionsThe study found a moderate rate of sexual assault in intimate violent partner relationships and those sexual assaults are more likely to co-occur with physical intimate partner violence and suicidal behaviour. This knowledge may be helpful in the detection and management of sexual assault in intimate violent partner relationships of women in health care settings in Thailand.