Background: Retention in care is required for optimal clinical outcomes in patients with HIV infection and ensures adherence to the antiretroviral therapy (ART). Unlike other PMTCT ART options, the current guidelines involve the initiation of life - long therapy regardless of their CD4 cell count. Little is known about the retention in care among newly diagnosed HIV infected women starting life-long treatment and the association of pregnancy status in Moshi municipality, Kilimanjaro, Tanzania. Broad Objective: This study aimed to determine the association of pregnancy status and retention in care among newly diagnosed HIV positive women initiated on ART in Moshi municipality. Methods: This was a retrospective cohort study design using routine data collected from 2 health facilities with both Ante natal and CTC clinics for HIV infected women. Data was extracted from only newly diagnosed HIV positive women who met the inclusion criteria. RESULTS: Of the women who started ART only 57.7% retained in care after five months. While about 42.3% nearly half 42.3% were not retained in care. I found higher loss to follow-up for those who attending their clinic at Pasua health center 57.3% compared to Majengo health center in which only 20.5%. There was no association between pregnancy status and retention in care among newly diagnosed HIV positive women initiated ART P-value 0.733 OR 0.91(95% CI 0.512-603). CONCLUSION: Retention in care in first five months is very low. Both health care provider and these patients are key factors to improve retention in care by providing health education on the importance of retaining in care.