Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset ataxia with pyramidal, cerebellar and distal neuropathic involvement. A cross-sectional study with 24 subjects was carried out to examine upper extremity aptitudes in ARSACS by comparing scores between two age groups (<40 and > or =40) and with reference values. Upper extremity aptitude measures included coordination, gross and fine dexterity, upper extremity strength, muscle tone, kinaesthetic sensitivity and global upper extremity performance. Functional aptitudes were evaluated with part of the Functional Independence Measure (FIM) and social participation was measured with the Assessment of Life Habits. Data showed significant differences between younger and older participants for coordination, gross and fine finger dexterity, pinch strength and global performance. Even the younger group had lower scores when compared with reference values. Functional aptitudes and social participation also showed differences between the two groups but the younger group had near normal performance as compared with reference values. This study demonstrated that upper extremity aptitudes related to coordination are affected early in the course of the disease. Functional independence and social participation showed a decrease performance later on and a high level of variability.