Adherence to antiretroviral therapy remains a challenge that has important implications for treatment success. The aim of this study was to assess the antiretroviral therapy among people living with HIV/AIDs in Anambra state between 2018-2020. Ex-post factor design was adopted for the study. The study was carried out in Anambra State of Nigeria. The population was made up of all confirmed HIV-positive clients currently accessing ART, in the 35 comprehensive facilities in Anambra state between 2018-2020 from 18 years and above. The sample size was 300 PLHIV/AIDs in Anambra state. Data that was collected from participants through response to the questionnaire questions as primary evidence and those collected from hospital ART registers by the researcher as secondary data was sorted, collated, compared, interpreted and analyzed for consistency with the application of relevant theories in the field of ART Adherence, mean was used to answer the research questions while t-test was used to test the hypothesis at 0.05 level of significance. From the results obtained based on the data collected and analyzed the following summary was reached. PLHIV/AIDs in Anambra state often adheres to ARV in terms of client pill count PLHIV/AIDs in Anambra state adheres very often to ARV in terms of client self-report. Percentage response to ART adherence by PLHIV/AIDs in terms physical assessment is high. There is an optimal level of adherence to ART by PLHIV/AIDs to laboratory investigation. There is an optimal level of adherence to ART by PLHIV/AIDs to pharmacy refill records. From the finding of the study, it can be said that there is an improvement in the level of adherence to ART by PLWHIV/AIDs in Anambra state. Though the level has increased, there has not been an optimal level of adherence by all the PLHIV/AIDs. There are patients who are not adequately adhering to ART in Anambra state. Therefore there is still need for proper sensitization on the need for adequate compliance to ART by PLHIV/AIDs in the state in other to achieve an optimal level of adherence.