The purpose of this study was to determine: 1) if proximal tibial epiphysiodesis (PTE) results in fibular overgrowth if performed without a concomitant proximal fibular epiphysiodesis (PFE); 2) if fibular overgrowth is prevented by concomitant PFE; and 3) the complications associated with PFE. There were 44 patients in the study, 33 who underwent PTE alone (group 1) and 11 who underwent PTE with concomitant PFE (group 2). Fibular overgrowth was measured at the knee and ankle. Proximal fibular overgrowth was significantly greater in group 1 (6.8 mm) than in group 2 (3.1 mm, = 0.02) or in the control group (1.2 mm, < 0.05) over a similar period of time. At the ankle, fibular growth was not significantly different between groups. There were no surgical complications related to PFE. PFE appears safe and should be considered if there is predisposing fibular overgrowth or several years of remaining growth.