A study was made of knee stiffness after fractures around the knee in patients with spina bifida. Thirty-one patients with 45 fractures were followed up for 2 to 15 years after the fracture. Knee stiffness was found in 67% of patients; this amounted to loss of up to half the normal range of movement. The stiffness appeared at two months from the time of the fracture and was established by six months. However, in all patients it had resolved by three years, so that their mobility was not affected in the long term. It is concluded that though stiffness is common after fractures in patients with spina bifida, it should be treated expectantly as it will resolve within three years without specific treatment.