OBJECTIVE To assess the outcome of micro-dissection testicular exploration sperm extraction (m-TESE) as a salvage treatment in men with non-obstructive azoospermia (NOA) in whom no sperm was previously found on single/multiple TESE or testicular sperm aspiration (TESA). PATIENTS AND METHODS In all, 58 men with NOA underwent m-TESE. All the patients had previously undergone either single/multiple TESE or TESA with no sperm found. All the patients underwent an m-TESE using a standard technique. Serum follicle-stimulating hormone (FSH), testosterone and histopathological diagnosis were examined as predictive factors for sperm recovery. All patients underwent preoperative genetic screening. One patient was found to have an azoospermic factor c (AZFc) micro-deletion and five were diagnosed with Kleinfelter's syndrome. RESULTS The mean (range) patient age was 39.0 (26-57) years. Spermatozoa were successfully retrieved in 27 men by m-TESE (46.5%). The mean (range) FSH level was 19.4 (1.6-58.5) IU/L. There was no correlation in age (mean age retrieved 38.1 years, not retrieved 39.7 years, P = 0.38), FSH levels (mean FSH retrieved 21.4 IU/L, not retrieved 17.7 IU/L, P = 0.3) and the ability to find sperm by m-TESE. However, there was a significant difference in testosterone levels and sperm retrieval (mean testosterone retrieved 14.99 nmol/L, not retrieved 11.39 nmol/L, P < 0.05). Patients with a diagnosis of Sertoli-cell-only (SCO) syndrome [14/35 (40%)] and maturation arrest [four of 11 (36%)] had lower sperm retrieval rates than those in the hypospermatogenesis group [nine of 12 (75.0%)] (P < 0.05). There were no significant complications after m-TESE. CONCLUSIONS In men with NOA who have undergone previous attempts at sperm retrieval with negative results, a salvage m-TESE offers a significant chance of finding sperm even in SCO syndrome. There does seem to be a correlation between preoperative testosterone levels and the ability to successfully find sperm.