Introduction: Highly specific, selective and accurate liquid chromatography/tandem mass spectrometry (LC__ampersandsignndash;MS/MS) technique was desirable for the assessment of apalutamide in human plasma. Aims: To develop and validate LC-MS/MS method for the analysis of apalutamide in human plasma. Methodology: Drug and internal standard were extracted utilizing liquid-liquid extraction was performed using ethyl acetate. Reversed-phase high performace liquid chromatography (RP-HPLC) was carried out using Inertsil (50__ampersandsigntimes;4.6 mm i.d., 5 __ampersandsignmicro;m) C18 analytical column with a simple isocratic mobile phase composed of 0.1% formic acid and acetonitrile, (20:80, v/v). Detection was executed on a triple quadrupole mass spectrometer retaining electrospray ionization method, operating in multiple reaction monitoring (MRM), with the transitions of m/z 478.09__ampersandsignrarr; 447.05, m/z 445.14 __ampersandsignrarr; 267.12 for apalutamide, canagliflozin, respectively, in the positive ionization mode. The linearity was processed a concentration range of 300__ampersandsignndash;12000 ng/mL for the analyte. Results: The method was validated in accordance with the FDA guidelines for bioanalytical method. All obtained recoveries were higher than 93.0% while the accuracy was in the range of __ampersandsignminus;4.32 to 2.45% of relative error and the relative standard deviation was below 4.21% for all investigated drugs by the proposed method. Conclusion: The validated method has highly sensitive and nice recoveries values from plasma, utilized for the bioequivalence and pharmacokinetic studies.