The liquid anti-solvent (LAS) precipitation process for production of ultra-fine particles has been widely employed for enhancing the solubility and dissolution rate of poorly water soluble drugs. In LAS process, precipitation of solute is achieved by decreasing the solvent power for the solute dissolved in a solution. A non-solvent or organic solvent for the drug is added to a polar or aqueous anti-solvent. The current research work endeavors to provide an account on the application of LAS for precipitation and stabilization of ultrafine micro or nanoparticles of poorly water soluble drug, Efavirenz, and comparison of its aqueous solubility and dissolution rate with β-cyclodextrin and hydroxypropyl-β-cyclodextrin inclusion complexes of the drug. Besides, the key aspects like controlling the particle size and size distribution, and stabilization of ultrafine particles using polymers has been studied. Applications of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and powdered X-ray diffraction (PXRD) techniques in physico-chemical characterization and evaluating the eventual transformation of solid state characteristics of the drug from crystalline to amorphous state has also been conducted. The findings of the work corroborated suggested the suitability of prepared polymeric drug micro or nano-crystals of Efavirenz in enhancing its solubility.