The need for reaming and the number of locking screws to be used in intramedullary (IM) tibial nailing of acute fractures as well as routine bone grafting of tibial aseptic nonunions have not been clearly defined. We describe the results of reamed interlocked IM nails in 233 patients with 247 tibial fractures (190 closed, 27 open and 30 nonunions). Ninety-six percent of the fractures were united at review after an average of 4.9 years. No correlation was found between union and nail diameter (P = 0.501) or the number of locking screws used (P = 0.287). Nail dynamization was effective in 82% of fractures. Locking screw(s) breakage was associated with nonunion in 25% of cases. Bone grafting during IM nailing was found not to increase the healing rate in tibial nonunions (P = 0.623). None of the IM nails were removed or revised due to infection. A dropped hallux and postoperative compartment syndrome were found in 0.8 and 1.6% of cases, respectively. Anterior knee pain was reported in 42% of patients but nail removal did not alleviate the symptoms in almost half. This series confirms the place of reamed intramedullary nailing for the vast majority of tibial diaphyseal fractures. It provides an optimum outcome and minimizes the need for supplementary bone grafting in aseptic nonunions.