Background and Aims: the most common compliant of post-operative orthopedic patients are pain and anxiety. But these compliant may be different in addict and non-addict patients. This study was conducted aiming at comparing the relationship between pain and state anxiety among addict and non-addict patients after lower limb orthopedic surgery. Method: this is a cross-sectional study conducted on 96 post-operative orthopedic patients. Study variables including pain and anxiety was measured with visual analogue scale for pain (pain-VAS) and state section of Spielberger state-trait anxiety inventory, 24 hour after patient’s surgery. Data were analyzed whit SPSS software using descriptive and analytical statistics (mean scores, chi-square, independent samples T test and Pearson correlation). Results: There were no significant difference between addict and non-addict patients in terms of mean score of pain and anxiety. Pearson coefficient for relationship between pain and anxiety for total sample, addict group and non-addict group was 0.538, 0.541 and 0.504 respectively, and P value for all was 0.000. Conclusion: results of our study showed a significant relationship between pain and anxiety among post-operative orthopedic patients, and this relationship was stronger in addict patients. Thus, pain and anxiety of these patients should be evaluated and treated properly for improving patient’s outcome and quality of cares.