Aim. Although several rehabilitation programs to improve functioning and pain after lumbar microdiscectomy have been suggested, little is known about the most effective exercise program. We aimed to investigate the effects of aerobic exercise program starting one month after single-level lumbar microdiscectomy on pain and functioning. Design. Prospective, non-randomized, controlled trial. Setting. Outpatient clinic. Population. Forty patients with single-level first-time lumbar microdiscectomy were included in the study. Eighteen patients were allocated to the aerobic exercise group while 22 patients to the control group. Methods. Both groups were given the same home exercise program. The exercise group received 20 sessions of treadmill exercise one month after the surgery in addition to the home exercise program. Low back pain and leg pain of the patients were evaluated by Visual Analogue Scale score (VAS), functioning was evaluated by Roland- Morris Disability Index (RMDI), anxiety and depressive symptoms were evaluated by Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI). Patients were evaluated within the last week before surgery, at the postoperative II and VIII month. Results. Significant improvements of low back pain VAS, leg pain VAS, functioning score, BAI score, BDI score were found in both groups after surgery (P<0.05). There was no significant difference in pain score, BAI score, BDI score change at II and VIII months between the groups (P>0.05). Functional improvement was significantly more pronounced in the aerobic exercise group than in the control group at the end of the aerobic exercise program (P<0.05). However, there was no significant difference in the numeric change of RMDI scores at VIII month (P>0.05). Conclusion. The results of this study showed that aerobic exercise starting one month after first time single-level lumbar microdiscectomy resulted in a more pronounced functional improvement than the home exercise program during the exercise sessions. It was seen that functional recovery did not last when exercise program was discontinued. Clinical rehabilitation impact. We suggest that suitable patients with single-level microdiscectomy should be encouraged to participate in aerobic exercise program one month after the surgery to regain functioning.