AbstractCoral reefs are subject to attack and predation by the starfish Acanthaster planci or crown‐of‐thorns. This paper describes a simulation model of the natural processes of a coral reef and its reaction to, and recovery from starfish attacks. The modelling of a reef section is based on a pixel representation of the area. On this are imposed the normal reef processes of coral recruitment, growth, competition and mortality. These were represented in computer form and a suitable computer package was produced and tuned to represent a typical hard coral mid‐shelf reef of the Great Barrier Reef. Fine tuning required the inclusion of a background mortality to ensure that the output extended over centuries, and exhibited the essential properties of real coral communities.The second phase of the simulation was to model the effects of a starfish attack, its likelihood of occurrence, strength and dietary preferences. Again, these may be tuned to represent the before and after effects of attacks as observed on the reef.The results of the simulations lead to the conclusion that the modelled coral community exhibited considerable stability (persistence and resilience) in the face of frequent and severe Acanthaster outbreaks. Regardless of the outbreak intensity, the coral community rapidly regained its pre‐outbreak cover of the area in about eight years. Some changes in the community composition were found in the periods immediately after outbreaks. However, the pre‐outbreak composition of the community was always restored within 20–30 years.