Totally Extraperitoneal (TEP) hernia surgery is associated with little postoperative pain and a fast recovery, but is a technically demanding operative procedure. Apart from the surgeon's expertise, patient characteristics and hernia-related variations may also affect the operative time and outcome. Patient-related factors predictive of perioperative complications, conversion to open anterior repair, and operative time were studied in a cohort of consecutive patients undergoing TEP hernia repair from 2005 to 2009. A total of 3,432 patients underwent TEP. The mean operative time was 26 min (SD ± 10.9), TEP was converted into an open anterior approach in 26 patients (0.8 %), and perioperative complications were observed in 55 (1.6 %) patients. Multivariable regression analysis showed that a history of abdominal surgery (OR 1.76, 95 per cent confidence interval 1.01-3.06; p = 0.05), and the presence of a scrotal (OR 5.31, 1.20-23.43; p = 0.03) or bilateral hernia (OR 2.25, 1.25-4.06; p = 0.01) were independent predictive factors of perioperative complications. Female gender (OR 5.30. 1.52-18.45; p = 0.01), a history of abdominal surgery (OR 3.96, 1.72- 9.12; p = 0.001), and the presence of a scrotal hernia (OR 34.84, 10.42-116.51, p < 0.001) were predictive factors for conversion. A BMI ≥ 25 (effect size (ES) 1.78, 95 % confidence interval 1.09-2.47; p < 0.001) and the presence of a scrotal (ES 5.81, 1.93-9.68; p = 0.003), indirect (ES 2.78, 2.05- 3.50, p < 0.001) or bilateral hernia (ES 10.19, 9.20-11.08; p < 0.001) were associated with a longer operative time. Certain patient characteristics are, even in experienced TEP surgeons, associated with an increased risk of conversion and complications and a longer operative time. For the surgeon gaining experience with TEP, it seems advisable to select relatively young and slender male patients with a unilateral (non-scrotal) hernia and no previous abdominal surgery to enhance patient safety and 'surgeon comfort'.