One component of the final report of a 3-year project to train speech language pathologists and audiologists to deliver services to young children (birth to age 5) with communication disorders, the paper provides a review of mainstreaming and an indepth view of its application at one center in Colorado serving young children with communication disorders. A brief review of the literature on mainstreaming precedes the description of the laboratory school program. Results of interviewing four preschool staff members regarding their perspective on mainstreaming indicated such benefits as observational learning by the handicapped child, improved self esteem for the handicapped child, improved speech/language development, improved cognitive development, more real world experience, and better parent training and support. Disadvantages of mainstreaming identified by interviewees included rejection of the special child by normal children and difficulty keeping up with the rapid pace in the mainstreamed setting. The importance of educator training for effective mainstreaming was stressed by all interviewees. Worksheets for program evaluation by teachers and directors are appended. (DB)