OBJECTIVE To observe the prevalence of anxiety and depression in chronic low back pain population at a tertiary care centre. METHODS The prospective cross-sectional study was conducted using convenience sampling at the Department of Neurosurgery, at Liaquat National Hospital, Karachi, Pakistan, from January to June 2010. The prevalence of anxiety and depression in chronic low back pain patients was studied according to specified age and gender groups using Hospital Anxiety and Depression Scale. RESULTS Of the 140 patients in the study, 66 (47.14%) were females and 74 (52.85%) were males.The average age of the patients was 43.02+/-13.34 years. The average duration of symptoms was 4.29+/-3.3 years. Abnormal level of anxiety and depression were found in 77 (55%) and 68 (48.57%) patients respectively. Out of them 54 (38.5%) and 51 (36.4%) were borderline abnormal for anxiety and depression respectively, while 23 (16.4%) and 17 (12.1%) were abnormal for anxiety and depression respectively. Among the males, there were 20 (14.28%) and 23 (16.42%) patients with abnormal levels of the corresponding numbers among the females were 57 (40.71%) and 45 (32.14%). There was a significant association in anxiety (p<0.01) and depression (p<0.01) levels with respect to gender and no significant association with respect to age (p>0.05). CONCLUSIONS Individuals with chronic low back pain were at high risk to experience anxiety and depression.This risk was higher for females.