Purpose The authors sought to determine whether a program of 5 weekly doses of milieu communication teaching (MCT) would yield improvements in children's communication and word use compared with a once-weekly delivery of the same treatment.

Method Sixty-four children with intellectual and communication delay were randomly assigned to receive 60-min sessions of MCT either 1 time or 5 times per week over a 9-month treatment. Growth curves were fit to data collected at 5 points before, during, and after the MCT was delivered.

Results With groups collapsed, significant growth across the experimental period was observed on all measures, but this was not associated unconditionally with treatment intensity. Children who played with 9 or more objects during a standard play assessment, an empirically identified cut-point, benefited more from the high- than from the low-intensity treatment on lexical measures (Hedges's g range = .49 to .65).

Conclusions More MCT is not always better for all children. Clinicians can expect that increasing the frequency of MCT sessions will yield moderate enhancement of outcomes if the child has high interest in objects.