Quality control (QuaCo) in urology is mandatory to standardize or even increase the level of care. While QuaCo is undertaken at every step in the clinical pathway, it should focus on the patient's comorbidities and on the urologist and its complication rate. Resulting from political and economical pressures, comparing QuaCo and outcomes between urologists and institutions is nowadays often performed. However, careful interpretation of these comparisons is mandatory to avoid potential discriminations. Indeed, the reader has to make sure that patients groups and surgical techniques are comparable, definitions of complications are similar, classification of complications is standardized, and finally that the methodology in collecting data is irreproachable.