Aim: HIV/AIDS continues to spread globally and remains a worldwide pandemic. Opportunistic infections (OIs) occur more and are severe in people living with HIV who have weakened immune systems, and co-infection is another major challenge because it affects the rate to which the disease progress to AIDS. In the present study, a total of 100 HIV positive patients were recruited and evaluated for the presence of common opportunistic infections (OIs) and co-infections among HIV-infected individuals in Port Harcourt, Nigeria. Study Design: Cross-sectional study. Place and Duration of Study: Prime Medical Consultants in Port Harcourt, Nigeria, between June 2012 and July 2015. Methods: A total of 100 HIV-infected individuals were recruited for this study (ages 1 to 70 years, 62 males and 38 females). Samples of blood, sputum, high vaginal swabs (HVS) and scrapped lesion from the mouth of the patients were collected. Blood samples were re-screened for the presence of HIV antibodies and HBsAg using the Determine HIV-1/2 (Alere), HIV ½ Stat-Pak (Chembio), HIV-1/2/P24/O ELISA kit and HBsAg one Ultra ELISA kit (Dia.Pro) following the respective manufacturer's instructions. The Ziehl-Neelsen sputum smear microscopy method was used for identifying tuberculosis (TB). Microscopical examination was done on HVS samples and lesions scrapings from the mouth to observe for Candida. Chi-square test was used to establish relationships between demographic factors and prevalence, and significance level was set at P ≤ 0.05. Results: Of the 100 HIV positive patients, suspected case were 32.0% of TB, 28.0% of oral thrush and vaginosis, and 19.0% of hepatitis. The results of the laboratory analysis further showed that tuberculosis was the most common OI among others. Overall prevalence was 22.0% for TB, 11.0% for Candida albicans (oral thrush), 28.9% for Candida albicans (vaginosis) and 4.0% for HBV.  Higher prevalence of TB was observed in the age groups 41 years & above (35.7%, P=0.14) and in males (22.6%, P=0.86). As for Candida albicans, the higher prevalence was found in age groups 21-40 years (19.1%, P=0.03) and in females only (28.9%), and higher prevalence of HBV was found in age groups 41 years & above (9.1%, P=0.78) and in females (5.3%, P=0.61). None of the variables (age and sex) evaluated in this study was statistically associated (P>0.05) with TB, Candida and HBV prevalence. Conclusion: The study has also shown that some opportunistic infections (candidiasis and Tuberculosis) and coinfections with HBV is prevalent among HIV infected individuals and this could largely be due to a compromised immune system as a result of the viral activities in the host cell. There is need therefore to routinely check for OIs and co-infections especially in the case of an immunocompromised individual. It is also imperative to note that the appropriate use of drugs against these OIs may be one of the strategies to extend the life span of AIDS patients. This will help to monitor how the disease progresses and its complications.