Communication impairments (CIs) in preschool children are common and can have long-term adverse consequences if not detected and treated early. This study investigated the knowledge, training and practice of primary health-care practitioners in the identification and management of CIs in preschool-aged children. A cross-sectional survey of 277 primary health-care practitioners in the Inner West and South West Sydney was undertaken. The majority of practitioners surveyed understood the importance of early identification of CIs. Eight per cent ofpractitioners correctly identified all of the 'red flags' for verbal and non-verbal communication. The majority (80%) correctly described the management of a typical case presentation. Two-thirds of practitioners reported using a tool in their practice for developmental surveillance, but the quality of surveillance tools was variable. One-third felt their training in this area was poor and 90% indicated they would like further training. Barriers to referral included waiting times, availability and cost of services. We concluded that primary health-care practitioners are aware that CIs are significant and they need to be identified early. There are opportunities for further training and promoting high-quality developmental surveillance in primary care. In addition, there are broader health system issues that include promotion of an integrated response to the detection and management of CIs.