This study explores whether firm characteristics such as size, ownership and industry sector influence the effectiveness of HR function or not. To examine the hypotheses, a questionnaire was developed and distributed towards 64 HR Professionals who attended Human Capital Forum at PPM Manajemen, Jakarta. Survey result indicated that except for industry sector, firm size and ownership did not affect the effectiveness of HR function. Mining and resource sector HR professional perceived that their industry sector was least effective in five effectiveness criteria compare to manufacturing and service sector.