Introduction: Women living with HIV may or may not intend to bear children. They may also have different preferences in terms of family sizes. The desire of HIV positive women to bear children and their family size preferences has significant implication for horizontal and vertical transmission of this incurable disease. This study, therefore, aims to determine fertility preferences and their predictors among HIV positive women accessing care at UPTH, Port Harcourt, Rivers State. Methods: The study was a descriptive cross-sectional study among 402 women within the reproductive age (15-49 years) who were on Antiretroviral Therapy (ART). Participants were recruited using systematic sampling method and were interviewed with an interviewer-administered questionnaire. A semi-structured, self-administered questionnaire was used to obtain participant’s socio-demographic characteristics, desire for children, use, demand and choice of contraception and reproductive characteristics. With SPSS version 20, data was summarised as descriptive statistics and Chi-square test was used to test for association. Results: The study showed that 81.8% of respondents desire to have children out of which 96 (29.3%) desired one to two children, 169 (51.5%) desired three to four children, and 18 (5.5%) wanted five or more children. Factors such as age, marital status, and disclosure of Sero-status to partner were found to be associated with family size preferences (p<0.05). Conclusion: HIV positive women in Port Harcourt have high fertility desires and moderate family sizes preferences; thus, indicating the need for more support and involvement of the government and relevant stake holders in ensuring better access to ART services in the country. More resources should be channelled towards provision of effective preventive medications and services, people who live with HIV (PLHIVs) should be continuously and adequately sensitised with the necessary knowledge on how to make healthy reproductive decisions, as well as on available practicable reproductive options for HIV-infected women should be made efficient, and easily accessible.