The aim of the present research work was to prepare and evaluate fast dissolving tablets (FDTs) of fixed dose combination (FDC) of anti-HIV drugs Ritonavir and Lopinavir with a view to enhance patient compliance and minimizes the side effects. In the cited study, fast dissolving tablets of Ritonavir and Lopinavir were formulated by direct compression method using freeze dried powder of Annona reticulata (Custard apple) pulp as a natural disintegrants and synthetic superdisintegrants like Crospovidone, Sodium Starch Glycolate (SSG) and Croscarmellose Sodium (Ac-di-sol) in different ratios with directly compressible mannitol as a diluent to improve the mouth feel. The prepared formulations were evaluated for various parameters including hardness, friability, drug content, in vitro dispersion time, wetting time, water absorption ratio, in vitro drug release studies, stability studies and excipients interaction studies. Among all the formulations, the formulation (FCA4) containing 5% w/w pulp of Annona reticulata was the overall best formulation based on in vitro drug release studies. Stability studies on selected formulations indicated that there were no significant changes in drug content and in vitro dispersion time. The final FDT was robust and disintegrated in 1 mL of fluid in 10 s with up to 4 tablets dissolving in 4 mL to achieve varying doses accommodated in a common teaspoon. From the above studies, it can be concluded that fast dissolving tablets of Ritonavir + Lopinavir can be prepared using different natural superdisintegrants for faster dispersion and disintegration in the mouth.