This retrospective study aimed to evaluate the factors that influence the final outcome of treatment of purulent flexor tenosynovitis, viz. delay in treatment, severity of the condition, the infecting pathogen and the method of treatment. Of 41 patients with this condition treated by drainage and irrigation through two small incisions (16) and wide incision (25), 16 were treated after a delay. Continuous postoperative irrigation was applied in 26 patients. Re-operation was necessary in 11 patients. In most cases, Staphylococcus aureus was detected. The results were excellent in 32 cases and the mean Disabilities of the Arm, Shoulder and Hand score was 8.1. Irrigation through small incisions and continuous postoperative irrigation decreased the probability of an unfavourable outcome. Delayed treatment and infections with specific pathogens led to a worse outcome. Early diagnosis of purulent flexor tenosynovitis followed by drainage through small incisions and continuous postoperative irrigation appear, from this retrospective review, to lead to the best functional outcome.