Primary school teachers generally have to teach several subjects. Their training, however, is often fairly short and it is tempting to force-feed them with everything they need to know to teach these subjects. It is more realistic to accept that a short course cannot do everything. Instead, it would be better to equip these students with skills that help them cope when their initial knowledge is weak. This study describes a problem-based learning (PBL) approach to skill development in science lesson planning where subject knowledge was initially weak. It examines student-teacher confidence in and satisfaction with this planning, motivation and feelings about collaborative work. Advice is offered on adopting a PBL approach for developing lesson planning skills.