An outbreak of post-operative wound infections due to Mycobacterium abscessus is described. During a 5-month period 45 post-surgical patients developed wound infection, manifested by wound breakdown, cellulitis, and discharge and progressing slowly to suppuration and sinus formation. The majority (43/45) had undergone out-patient operations, and 40 had had surgery in the inguinal region. The source of infection was identified as contaminated tap water. A study revealed serious deficiencies in the disinfection and sterilisation techniques employed in the operating theatre (OT), including major defects in the autoclaving machine. The outbreak was controlled after several specific measures were instituted. The patients responded well to treatment with conventional first-line anti-tuberculous drugs administered for 3-8 months. The report highlights the necessity of strict monitoring of disinfection and sterilisation techniques in surgical units and OTs.