The purpose of this study was to assess if primary closure of wounds on a suction drain can be performed in open fractures after debridement and to determine the risk of infection and nonunion. A total of 78 type II and type IIIa open fractures were managed with primary closure on a suction drain. They were followed until union. Rates of infection, delayed union and nonunion were determined and compared with rates reported in the literature. Overall, 16 fractures (20.5%) were complicated with superficial infections and 8 fractures (10.2%) had deep infections. Delayed union was observed in 11 fractures (14.1%) and nonunion in 12 fractures (15.3%). Primary closure of a wound on a suction drain seems to cause no significant increase in rates of infection, nonunion or delayed union.