A stability-indicating micellar electrokinetic chromatography method has been developed and validated for determination of finasteride. Analysis was performed by using 50 cm × 100 μm i.d. (effective length 42.8 cm) fused silica capillary and background electrolyte of 50 mM NaH2PO 4 (pH 3) buffer containing 10 mM sodium dodecyl sulfate as surfactant. Applied potential was selected as -15 kV at 25°C and the detection was at 210 nm. The calibration curve was linear in the range of 5-50 μg · mL-1. Effects of pH, capillary temperature, applied voltage, and buffer concentration were investigated. Degradation studies were carried out under acidic (1.0 M HCl), basic (1.0 M NaOH), oxidative (%10 H 2O2), thermal (60°C), and UV-light (254 nm) conditions and it was found that finasteride was degraded under acidic, basic, and oxidative stress conditions. The method was successfully applied to the determination of finasteride in tablet formulations. Copyright © Taylor & Francis Group, LLC.