Recent studies suggest that the prevalence of hypothyroidism among human immunodeficiency virus (HIV) people who were on treatment with highly active antiretroviral therapy (HAART) was higher than that in treatment naïve HIV infected people and those who were not infected with HIV. This study looked at the prevalence of hypothyroidism in HIV infected people who are on HAART and the presence or not of other thyroid abnormalities in these patients. A total of 128 participants were randomly recruited for the study, made up of the test population (n = 76), who were HIV positive on HAART, the control-HIV population (n = 24) who were treatment-naïve and the control-normal population (n = 28). Blood samples were collected for thyroid stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) using a chemiluminescence based third generation thyroid assay. A total prevalence of thyroid abnormalities of 26.3%, 33.3% and 7.2% were observed in the test subjects, control-HIV and control-normal groups respectively. Low FT3 and FT4 with normal TSH values was observed in 6.6% (n = 5) and 8.3% ( n = 2) of the test subjects population and the control-HIV population, while 7.9% (n = 6) and 12.5% (n = 3) of the test subjects and control-HIV populations had isolated low FT3 and FT4 values respectively. 1.3% (n =1) of the test population had subclinical hyperthyroidism. These are compared with the control -normal population only one person each had subclinical hyperthyroidism and isolated low FT4. This study thus concludes that, there is apparently a high prevalence of both thyroid dysfunctions and nonthyroidal illness (NTI) among HIV infected people, whether treatment naïve or on HAART.