This study explores the factor structure of job performance and each performance dimension's relative importance in determining supervisors' overall job performance ratings. We found that the optimal factor structure of job performance includes five dimensions: task performance, organizational citizenship behaviour directed toward the organization and individuals (OCB‐O and OCB‐I, respectively), and counterproductive work behaviour directed toward the organization and individuals (CWB‐O and CWB‐I, respectively). The percent‐based relative weight (%RW) is the highest for task performance in determining job performance, followed by OCB and CWB. Interestingly, the %RW of non‐task performance dimensions directed toward the organization (OCB‐O and CWB‐O) is similar to the %RW of task performance but greater than the %RW of non‐task performance dimensions directed toward individuals (OCB‐I and CWB‐I).