Introduction. Given the rising incidence of obesity in the adult population, it is more than likely that orthopaedic surgeons will be treating more obese patients with lumbar disc pathologies. The relationship between obesity and recurrent herniated nucleus pulposus (HNP) following microdiscectomy remains unclear. Objectives. To investigate the relationship between obesity and recurrent HNP following lumbar microdiscectomy. Methods. A retrospective review of case notes from 2008–2011 was conducted for all patients that underwent one level lumbar microdiscectomy, performed by a single surgeon. The standard criteria for microdiscectomy were used. Patient demographics, including Body Mass Index (BMI), collected from notes. Obese patients classified as BMI >/= 30. The primary clinical outcome measure was evidence of recurrent HNP on post operative MRI scan requiring further surgery. Results. A total of 283 patients were available for analysis: 190(67%) were in the non-obese group and 93 (32.9%) in the obese group. The average BMI was 28.1 and the average length of stay was 1.3days. Dural leak was seen in 11 patients(3.9%) out of which 8(4.2%) occurred in the non-obese group and 3(3.2%) in the obese group [p=0.04]. Recurrent symptomatic HNP was seen in 27(9.5%) patients confirmed by MRI scan. 19(10%) were in the non-obese group and 8(8.6%) in the obese group [p>0.8]. Conclusion. Obesity was not a predictor of recurrent HNP after lumbar microdiscectomy and did not have increased complication rates compared to the non-obese group