Abstract To determine the impact of an experimental approach to case management on use of child health clinic and immunization services, a nonequivalent control group with covariate measures design was employed in a sample of 98 infants from low-income families. The innovative pattern of care featured continuity of care; a single public health nurse (PHN) provided child health care to an infant by integrating case management and preventive services. In contrast, the customary pattern of child health care was characterized by fragmentation of services. Case management was segregated from preventive services, and multiple PHNs delivered care to an infant. As predicted, experimental-group infants (44%) were more likely to achieve adequate child health clinic services than control-group infants (8%) (p < 0.001). Moreover, the cost-effectiveness (C/E) ratio (dollar cost per effective intervention) for adequate child health clinic visits in continuous care ($523) was one-fifth of that in fragmented care ($2,900). The C/E ratio related to adequate immunization was 8% less in continuous care ($359) than in the fragmented approach ($386), although the difference in rates of adequate immunization was nonsignificant (experimental group, 64%; control group, 60%). These findings suggest that continuous PHN care with integrated case management is a more effective, cost-efficient approach to critical child preventive services than the customary, segregated case-management approach.