In this work a numerical method, based on the use of spectrophotometric data coupled to Principal component regression (PCR) and Partial least squares (PLS) multivariate calibration, is evaluated for the simultaneous determination of Diacerein and Aceclofenac in bulk and tablet dosage form. Spectra of Diacerein and Aceclofenac were recorded at concentrations within their linear ranges 2-12 μg/ml and 5-30 μg/ml, respectively and were used to compute a total of 51 synthetic mixtures involving 36 calibration and 15 validation sets in the wavelength range of 200-400 nm with the wavelength interval of λ=0.5 nm in methanol. The analytical performances of these chemometric methods were characterized by relative prediction errors and recovery studies (%) and were compared with each other. These two methods were successfully applied for estimation of drugs and pharmaceutical formulation (tablet) with no interference with excipients as indicated by the recovery study results. The proposed methods are simple, rapid and can be easily used as an alternative analysis tool in the quality control of drugs and formulation.