The association of COVID-19 and HIV infection would seem deadly in terms of prognosis and the possibilities of viral clearance given the immunodeficiency. However, a lower seroprevalence has been reported in some studies compared to that found in the non-HIV population. The objective of this study is to determine the seroprevalence of COVID-19 among people living with HIV (PLHIV) in Morocco. This is a prospective study carried out in the infectious diseases department of the Ibn Rochd University Hospital in Casablanca. We included PLHIV who consulted the Infectious Diseases Day-Hospital service between January 18, 2021 and March 10, 2021. After informed consent, patients completed a survey and had blood drawn for SARS-CoV-2 antibody testing. The determination of IgG antibodies against SARS-CoV-2 in blood was carried out using chemiluminescence microparticle immunoassay technology. We included 418 PLHIV in the study, most patients were male (50.24%), the average age was 40 years, 90.2% of patients were on antiretroviral treatment, 56.7% had a viral load <20 copies/ml, and 47.37% had a CD4 count greater than 500 cells/μL. The IgG test was positive in 53 patients, representing a seroprevalence of 12.68%. None of the patients had clinical signs. Seroprevalence was higher in female patients (58.49%), aged between 30 and 40 years (41.51%), in patients with a negative viral load (64.15%) and a CD4 count greater than 500 cells/mm3 (49.6%). Our study showed that the seroprevalence of COVID-19 was higher among PLHIV compared to people without HIV infection. All the patients had asymptomatic forms which pushes us to evoke a theory, to demonstrate, of the action of antiretrovirals against SARS-CoV-2.