Time out has been widely advocated as an effective parental discipline practice to reduce disruptive and oppositional child behaviour in young children. Despite evidence showing that the procedure is effective when used as part of a comprehensive positive parenting strategy it has not been uniformly accepted and critics have questioned its effectiveness and potentially adverse effects on the parent-child relationship. This paper examines the controversy surrounding the use of time out, discusses the criticisms levelled against it, and concludes that its judicious use in parent training programs is justified and is of benefit to many children with conduct problems. Factors that influence the effectiveness of time out and some contraindications are also discussed.