We have found in our clinic a 28.1% prevalence of familial chondrocalcinosis among 149 family members of 32 patients with calcium pyrophosphate dihydrate deposition disease. The clinical and radiological characteristics of these familial chondrocalcinosis patients were similar to those of the Chiloes with familial chondrocalcinosis previously reported. No significant clinical or radiological differences were detected between our sporadic and familial chondrocalcinosis patients. Our findings support the hypothesis that the Chiloes familial chondrocalcinosis was carried to Chile by Spanish immigrants.