Primary health care nurses are frequently overlooked when delivering services to children with developmental disabilities, despite the fact that they are often the first contact many primary caregivers have with rehabilitation professionals and usually remain the bridge between caregivers and professionals. A time series one group design with withdrawal was used to evaluate an in-service training programme for primary health care workers aimed at facilitating beginning communication skills between primary caregivers and their children with developmental disabilities. Training employed adult learning principles and was one week long, followed by three follow-ups that were conducted in situ (at two weeks, six weeks and five months post-training). Multiple measurements were used to evaluate the knowledge and skills acquired after training, namely questionnaires, structured interviews, skill demonstrations (which were video recorded and rated by the researcher and an independent rater) and a focus group. Results indicated that the particular in-service training programme was relevant in bringing about a significant change in the targeted domains, namely knowledge and skills. (Contains 5 tables and 2 figures.)