A worker management system, which includes a plant 100 divided into a plurality of work areas each in correspondence to specific task contents, a database 220 having stored therein task identification information correlating each work area 112 with contents of tasks performed therein and worker detection sensors 130 installed in each work area, identifies the specific work area where a worker is currently located based upon outputs from the worker detection means and then identifies the task currently performed by the worker based upon the task identification information. Based upon the current task thus identified, a decision is made as to whether the worker should continue the current task or be assigned a new task and an instruction for task execution is issued to the worker. Therefore the identification of current tasks, the assignment of a new task and the task reassignment are facilitated to improve the work efficiency.