Abstract: A three-durg antiretrovial pharmaceutical composition having a selective combination of a controlled release active formulation and an immediate release active formulation for once daily administration. The composition provides desired dosages of the actives lamivudine, zidovudine or pharmaceutically acceptable derivatives thereof, and the immediate release formulation including atleast one selective Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI), preferably nevirapine or a pharmaceutically acceptable derivative thereof alongwith pharmaceutically acceptable excipients. The once daily composition would favour patient compliance and effective treatment. A method of reducing the pill burden in a patient suffering from HIV infection and/or Acquired Immunodeffieciency Syndrome by administering a once daily of the three-durg antiretroviral pharmaceutical composition.