Background Time-out (TO) is a widely used parental discipline strategy with strong research support in programmes that promote positive child development. Concerns have been raised, however, regarding adverse impact on child mental health (CMH) in part driven by evidence of widespread variability in appropriate implementation. There are no existing measures of TO. We present the first measure of procedural implementation of TO in a community sample of parents of children aged 6–8 years. Methods A nationally representative sample ( N = 474) of parents completed a survey on the implementation of TO, parent-child relationships, and emotional and behavioural difficulties. The scale of TO use was used to test the convergent validity between TO implementation and parenting practices/family adjustment and CMH. Results Consistent with international research, >70% of parents have used TO with their children. There was high variability in the levels of appropriate implementation of TO. Scale reliability (Cronbach’s alpha) was acceptable and tests of convergent validity indicated that as expected, less appropriate implementation of TO was associated with worse CMH and poorer parenting and family adjustment. Conclusions The current findings suggest that the scale is a psychometrically sound instrument for measuring the appropriate procedural implementation of TO with young children.