The case cards for autopsied patients with Fukuyama type congenital muscular dystrophy (FCMD) which included clinical data and pathological findings were filled in 10 national hospitals and 2 other institutes in Japan. The cards of 24 patients who died between 1978 and 1991 were collected and analysed for this study. The ages at death ranged from 2 to 27 years with a mean of 14.29 +/- 6.18 years and represented a nearly unimodal distribution. The age at death in the 12 patients who died before 1983 ranged from 2 to 21 years and averaged 11.58 +/- 5.11 years, whereas the 12 patients who died after 1984 ranged from 3 to 27 years of age and averaged 17.00 +/- 6.44 years. The latter group lived significantly longer than the former (p < 0.05). Pulmonary infection was a more frequent cause of demise in the group of patients who died before 1983 than in those who died after 1984 (83.3% vs 25.0%). On the other hand, cardiac failure was a more common cause of death in the latter group (8.3% vs 50.0%). These data on the life spans and cause of death of FCMD were similar to those studied of Duchenne muscular dystrophy by Mukoyama et al (1984, 1986, 1987).(ABSTRACT TRUNCATED AT 250 WORDS)