Aim The objective of this study was to determine the effect of anxiety on intrauterine insemination (IUI) results in couples with unexplained infertility. Second, the relationship between difficulty level of IUI procedure and anxiety were investigated. Methods A total of 100 women undergoing first IUI treatment were enrolled into this prospective cross-sectional study. Participants were asked to complete the Beck Anxiety Inventory (BAI) before the IUI procedure and classified into two groups according to the anxiety score (minimal anxiety; BAI score <8,n= 73 and mild-to-moderate anxiety; BAI score >= 8,n= 27). Cervical condition was evaluated with speculum and presence of congenital anomalies, extensive leucorrhea or polypoid lesions were classified as unfavorable cervix. All of the patients were evaluated for difficulty of IUI and asked to state the severity of their pain with a visual analog scale after the procedure. Clinical pregnancy rates were also analyzed. Results There was no statistically significant difference between the groups in terms of pregnancy rates (12.3% vs 14.8%,P= 0.743). visual analog scale score was significantly higher in mild-to-moderate anxiety group (P= 0.002). Anxiety levels were higher in patients with difficult IUI (10.5 vs 4.3,P < 0.001). In multivariate analysis, higher BAI scores (odds ratio: 1.1, 95% confidence interval: 1.0-1.2,P= 0.01) and unfavorable cervical condition (odds ratio: 3.6, 95% confidence interval: 1.2-10.7,P= 0.01) emerged as independent predictors for difficulty of IUI. Conclusion Evaluation of anxiety before IUI might help to predict difficulty of IUI and related pain. Although anxiety increases the difficulty of IUI, it does not affect pregnancy outcomes of the treatment.