Background: Oral candidiasis has been a global health challenge especially in immunocompromised patients particularly with HIV infection. Though the incidence and prevalence of opportunistic infections have been reduced due to the use of anti-retroviral therapy (ART), oral candidiasis remains the most frequently HIV-associated oral lesion in Tanzania. This study aimed at determining the prevalence of oral candida infection in HIV positive patients and investigate the relationship between oral manifestations and the level of immunosuppression. Method: This study was carried out at Kilimanjaro Christian Medical Centre in Moshi, Tanzania. The study included 314 HIV patients with complete clinical results records who were diagnosed with HIV and who were on ARV and attending the hospital for care and treatment. Results: Prevalence of oral candida was 42.0% (132/314). Age group 6-27 years accounted for half of the infections (49/98).  A significantly higher prevalence of candida infection  (66.7%; 24/36) was obseved among patients with <200 cells/µl than in those with 200-500 cells/µl or >500 cells/µl (Chi-square χ2=14.9, p=0.001). The mean CD4+T-cell counts in HIV patients infected with oral candida was lower (523±35) than patients without oral candida infection (645±31 cells/µl), (ANOVA, p= 0.009). The mean CD4+ T-cell count among HIV patients on ART and those not on ART was not statistically different. Conclusion: The prevalence of oral candida infection was significantly higher in patients with CD4+ cell counts less than 200 cells/µl.