To appraise the economic burden for families of patients with type 1 diabetes mellitus (DM1) at the Instituto Nacional de Pediatria in Mexico City. DM1 family direct costs were obtained from a standardized economic survey in 59 children with no chronic severe complications such as kidney failure in 2002-3. Mean family annual direct cost of treatment and monitoring was US $1689.87 which includes government funding given to both outpatients and inpatients. Despite this, DM1 out-of-pocket cost for families is very high compared to the minimum official wage of approximately $4.00 dollar/day versus $4.06 cost DM1/day. No correlation between parents' age, education or socio-economic level and direct cost was statistically significant. The highest economic burden was due to self-monitoring of blood glucose (SMBG) 53.0% and insulin 14.8%. The costs were higher in children with poor metabolic control who performed SMBG less often.