The aim of our project has been to develop formulation of Nanocrystals of an anti-leprotic drug Clofazimine, in order to improve its oral bioavailability. Clofazimine nanocrystals were prepared by anti-solvent precipitation method. In vitro data obtained for Clofazimine nanocrystals showed good entrapment efficiency and sustained drug release. From the results it can be concluded that the drug release from the nanocrystals were controlled by the surfactant tween 80. The solubility and in vitro dissolution studies suggested that the nanocrystal formulations can improve the bioavailability of the Clofazimine by improving its solubility and dissolution rate. The in-vitro diffusion studies were performed in phosphate buffer. tween 80 releases 90% of the drug within 3 hrs but in case of PVP and combination of PVP and tween 80, the release was extended to 4 hrs. PVP releases only 80% of drug in 4 hrs but combination of PVP and Tween formulations release maximum amount of drug i.e., 99% within 4 hrs. Hence, it was concluded that nano crystallization was a good approach to enhance the solubility and dissolution property of Clofazimine by nanoprecipitation technique and also sustained the drug release by using Tween 80 as surfactant and PVP as a stabilizer. Thus, nanocrystal drug delivery system can have adopted to increase the solubility and dissolution rate of poorly soluble drug like paclitaxel to enhance their bioavailability. Key words: Formulation, Optimization, Clofazimine, Nanocrystals, Bioavailability