Aims: The aim of the present work was to develop and validate a sensitive, simple, accurate, precise & cost effective UV spectrophotometric method for the estimation of haloperidol in prepared pharmaceutical formulations of solid lipid nanoparticles. Methodology: The different analytical performance parameters such as linearity, range, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization (ICH) Q2 (R1) guidelines. The study was performed in phosphate buffer of pH 7.4. Results: The peak (λmax) of haloperidol appeared at a wavelength of 247.5 nm in phosphate buffer (pH 7.4). Beer-Lambert’s law was obeyed in the concentration range of 2–20 μg/ml with correlation coefficient (R) 0.9994. Conclusion: The results of the study demonstrated that the developed procedure was accurate, precise and reproducible, while being simple, cheap and less time consuming. Original Research Article British Journal of Pharmaceutical Research, 4(11): 1407-1415, 2014 1408 Therefore, this method can be suitably applied for the estimation of haloperidol in prepared solid lipid nanoparticles.