A Volunteer Lake Monitoring Program initiated by the Illinois EPA in 1981 was continued in 1989. Citizens were trained to measure Secchi disc transparency, total depth, and record field observations from a boat at designated sites on their chosen lake. Readings were to be taken at least twice a month from May through October, and the results forwarded to the Agency. In addition, volunteers for 43 lakes collected water samples for analysis of nutrients and suspended solids when performing the Secchi monitoring. The report provides a historical perspective of the Volunteer Lake Monitoring Program and describes program objectives and rationale. Two hundred and twenty-five volunteers participated in monitoring 160 lakes in 1989; 139 lakes had data for 4 or more sampling periods and are included in the report.