BACKGROUND The correlation between hamstring muscle shortening and nonspecific low back pain and compensatory lumbar movements is still controversial. The purpose of this study was to evaluate the association between hamstring shortness and asymmetry, pain intensity, the disability index, and compensatory lumbar movement in 60 patients with nonspecific chronic low back pain. MATERIAL AND METHODS Sixty patients with nonspecific low back pain participated in this study. The hamstring shortness and asymmetry, pain intensity, the disability index, and compensatory lumbar movement of the patients were assessed. The pain intensity was evaluated using a numeric pain rating scale (NPRS), active knee extension testing was performed to measure the length of the hamstring, and compensatory lumbar movement was assessed using a digital dual inclinometer. Correlation analysis was used for analysis of the obtained data. RESULTS The hamstring length showed a negative correlation with hamstring length asymmetry, NPRS, and disability index (P<0.05). The asymmetry of the hamstring length was positively correlated with NPRS, disability index, and compensatory lumbar rotation (P<0.05). Lumbar flexion was positively correlated with the hamstring muscle length (P<0.05). However, there was a negative correlation between the hamstring length asymmetry, NPRS, and disability index (P<0.05). There was no correlation between the compensatory lumbar rotation, hamstring length, or disability index. CONCLUSIONS Compensatory flexion movements, NPRS, and disability index in patients with nonspecific chronic low back pain were associated with hamstring shortness and asymmetry. These factors should be considered when planning physical therapy for patients with nonspecific low back pain.