In Mexico, people utilize public, private and traditional health providers interchangeably and in contrast to official access policies. Access policies for prenatal and child delivery services are evaluated using data from the National Health Survey of 1988. The study documents significant coverage gaps on the part of public providers with respect to their potential coverage, and especially, large cross-utilization of social security, Ministry of Health and private providers by beneficiaries. Child deliveries in Mexico are attended by a physician in only 66% of cases. The percentages are 85% for social security affiliates, 53% for women within reach of IMSS-Solidarity services (a relief programme for the rural poor) and only 31% for women with official access to private or Ministry of Health care, or beyond the reach of services. Seventy-eight per cent of medical deliveries by women affiliated to social security occur at their pre-paid facilities, while 14% deliver at extra cost with private physicians, contributing to 32% of deliveries so offered. Even though only 7% of insured women deliver at Ministry of Health facilities, this amounts to 20% of the Ministry's relief offer. In all, only 66% of affiliates use social security delivery services. On the other hand, 36% of deliveries by non-insured women are cared for by Ministry of Health providers, and 39% by the private sector; 22% of such deliveries occur in social secury institutions, amounting to 18% of these institutions' care offer.