Many learners find the study of introductory computer programming difficult. This is also true of children with attention deficit hyperactivity disorder (ADHD) and, in order to support them, we need an improved understanding of how they learn programming. This study explored strategies for constructive learning of introductory programming by children with ADHD. The aim was to evaluate the effectiveness of the Karplus learning cycle--a constructivist teaching tool--to teach introductory programming to these learners. Working from an interpretive perspective, data was gathered through action research techniques and analysed using grounded theory methods. Four major constructivist teaching categories emerged, all of which support the use of the Karplus cycle. We concluded that--with some augmentation--the Karplus cycle can be used to assist learners with ADHD to learn introductory programming. We recommend that, to ensure effective learning, the middle phase of the three-phase cycle should be expanded into two sub-phases, and suggest two alternative ways to do this.