In present study, solid dispersion (SD) of ritonavir was prepared to enhance its aqueous solubility. The SD was prepared by using polyvinyl pyrrolidone vinyl acetate as a carrier with different drug polymer ratios using spray drying technique. The formulation was characterized using differential scanning calorimetry (DSC), X-ray diffraction (XRD), in-vitro dissolution and in-vivo absorption studies. Intrinsic dissolution rate study was performed to find the impact of increased solubility on the dissolution rate. DSC and XRD analysis demonstrated the conversion of ritonavir to amorphous form. SD showed 95% release in 25 minutes as compared to 20% of drug release in 60 minute form physical mixture. in-vivo study result indicated that SD exhibited significant increase in area under concentration with time (AUC) and maximum concentration (Cmax).