Among HIV-infected women, unprotected sex with the main sexual partner is common practice. Conversely, studies about condom use with sexual partners of unknown HIV sero-status are sparsely reported. We aimed to assess the impact of oral contraception on unsafe sexual behaviours with occasional partners in women HIV-infected through injection drug use. The analysis focused on 90 women, enrolled in the French cohort MANIF 2000 and reported having engaged in sexual relationships with occasional partners during a 48-month period. Visits where women reported unprotected sex with occasional partners in the prior 6 months were compared to visits where they reported protected sex using a logistic model based on Generalised Estimating Equations. Unprotected sex with occasional partners was independently associated with oral contraception (OR[95%CI] = 3.2[1.4-7.2]), reporting only one occasional partner (OR[95%CI] = 3.1[1.6-6.2]) and antiretroviral treatment receipt. No significant association was found between unprotected sex and CD4 level or plasma viral load. With the growing population of people living with HIV as a chronic infection, the development and evaluation of HIV-prevention interventions tailored toward women remain a public health priority. Risk reduction counselling and interventions are needed to promote either the use of dual contraception or, alternatively, that of female condom.