The purpose of this study was to evaluate the prognostic value of the ratio of preoperative neutrophil to lymphocyte after intravesical BCG treatment in non-muscle invasive bladder cancer (NMIBC). The data of 89 patients, operated for urothelial carcinoma and treated with BCG after the diagnosis of NMIBC between 2007 and 2014, were reviewed retrospectively. Preoperative complete blood counts and first cystoscopic examination findings of the patients were examined. Median follow-up was 28.7 months. Tumour recurrence was detected in 33 patients (Group 2) of 89 patients. There was no tumour recurrence in 56 patients (Group 1). Neutrophil/lymphocyte ratio, MPV and CIS incidence were significantly increased in Group 2. This study showed that, preoperative high neutrophil/lymphocyte ratio, MPV and CIS occurrence can be used as independent criteria to predict tumour recurrence after intravesical BCG treatment in NMIBC.