In this study, a simple, sensitive and highly accurate ultraviolet spectrophotometric method has been developed and validated for determination of atenolol in bulk and pharmaceutical formulations. The method is based on the measurement of the absorbance of atenolol solution in methanol: phosphate buffer pH 6.8 (10:90) at 224 nm in the wavelength range of 200 - 400 nm. Beer’s law was obeyed in the concentration range of 5-25 µg/mL. The slope, intercept and correlation coefficient were also calculated. Results of percentage recovery shows that the method was not affected by the presence of common excipients in tablets. The developed method was validated in terms of accuracy, precision, linearity, limit of detection, limit of quantification which proves suitability of proposed method for routine estimation of atenolol in bulk and pharmaceutical formulations.