Tendon injuries to the thumb are uncommon in children. Nine children (mean age 6.1 years) with isolated complete injuries to the flexor pollicis longus (FPL) were treated with primary suture and controlled mobilisation at a major referral centre between 1985 and 1992. Five injuries occurred in zone II, two in zone III and two in zone V. One child developed sepsis and there were no cases of tendon rupture. Good or excellent results (Buck-Gramcko criteria) were achieved in seven of the nine children. Pinch grip after repair was similar to the non-injured hand. Primary repair and early controlled mobilisation of FPL leads to satisfactory results in children.