Objective: to evaluate the outcome of intracytoplasmic sperm injection (ICSI) cycles in patients with obstructive azospermia undergoing fine needle sperm aspiration compared to open testicular biopsy. Design: Retrospective study. Materials/Methods: Between May 1994 and November 2000,a total of 245 patients underwent 329 cycles of ICSI with surgical sperm retrieval. Only patients with obstructive azospermia (n = 174 patients, 190 cycles) were included. They were divided into 2 groups based on the technique of sperm retrieval: Group 1 (n = 146) underwent fine needle sperm aspiration (72 testicular and 74 epididymal) while group 2 (n = 44) underwent open testicular biopsy. Mean female age was 33.9 ± 6.3 and 33.8 ± 5.6 years in the 2 groups respectively. Statistical analysis was done with analysis of variance or χ2 test with p < 0.05 considered statistically significant. Results: There was no significant difference among the 2 groups in age, stimulation, downregulation protocol, number of eggs retrieved, number of embryos transferred or method of embryo transfer. Outcome of ICSI following surgical sperm retrieval in the 2 groups of obstructive azospermia is shown in Table 1. Among patients with obstructive azospermia undergoing testicular sperm aspiration (n = 72 cycles), ongoing pregnancy rate per cycle and embryo transfer were 27.8% and 28.2% respectively compared to 36.5% and 37.5% in patients undergoing epididymal sperm aspiration (n = 74 cycles). The difference was also not statistically significant (p 0.05).Table 1Outcome of ICSI in patients with obstructive azospermia undergoing sperm aspiration vs testicular biopsy.Sperm aspiration (n = 146)Open biopsy (n = 44)Motile sperm recovery rate %83.681.8 ∗Difference is not statistically significant (p > 0.05).Fertilization rate %61.966.2 ∗Difference is not statistically significant (p > 0.05).Implantation rate %11.711.7 ∗Difference is not statistically significant (p > 0.05).Clinical pregnancy rate/embryo transfer %43.431.8 ∗Difference is not statistically significant (p > 0.05).Ongoing pregnancy rate/embryo transfer %32.929.5 ∗Difference is not statistically significant (p > 0.05).∗ Difference is not statistically significant (p > 0.05). Open table in a new tab Conclusions: Fine needle sperm aspiration resulted in similar fertilization, implantation and pregnancy rates compared to open testicular biopsy in patients with obstructive azospermia. Pregnancy rates were also comparable with testicular and epididymal sperm aspiration. As a less invasive and technically easier procedure, fine needle sperm aspiration is recommended for surgical sperm recovery in patients with obstructive azospermia compared to open testicular biopsy. Supported by: IVF Michigan, Michigan State University.