An efficacy study of an indirect or Parent-based intervention programme involving Video Home Training (PVHT) was conducted with a focus on parental strategies to (re-)establish coherence in conversations between young children with Developmental Language Delay (DLD) and their parents or caregivers. In order to assess the efficacy of the PVHT programme, linguistic and conversational coherence outcomes were compared to those for a Direct Child language Intervention (DCI) programme. A randomized controlled group design with follow-up measures was used: there were 11 children with their parents in the PVHT group and 11 children with their parents in the DCI group. Compared to the DCI programme the PVHT programme showed significant short-term and long-term effects on mean length of utterance, grammar, language comprehension and conversational coherence at post-treatment and follow-up. The results are discussed in light of previous studies, VHT and the PVHT-focus on parental training of strategies to create conversational coherence. (Contains 2 tables and 4 figures.)