Breeding platypuses (Ornithorhynchus anatinus) in captivity had proved difficult until the last 10 years but with improvements in husbandry and a greater understanding of platypus biology there have been seven successes at two institutions since 1998. This study, using closed circuit video monitoring, took place between 2001 and 2007 at Taronga Zoo and covered three breeding successes with one female in 2002/03, 2004/05 and 2005/06. Results have revealed a consistency of behavioural patterns, which accurately predicted breeding events, mating, burrow construction, subsequent denning period and emergence of young. The female platypus had a receptive period of 4–6 days in the spring of each year, during which her behaviour changed from avoidance to initiating contact with the male. After mating she immediately commenced burrow preparation, ending with a 3–5-day intense period of collecting wet nesting material before retiring to the burrow to lay. The gestation period was estimated at 15–21 days and incubation at less than 12 days. A suckling period of 114–127 days followed, with the frequency of maternal burrow visits and length of stay decreasing as the juveniles grew. Juveniles emerged 133 ± 4 days after retirement. This study provides new and important information about breeding behaviour in this species and will contribute to future breeding success of platypus in captivity.