The paper discusses the topology of the skin -friction line pattern on a 65 -deg swept delta wing with special attenti on to the flow on the apex that usually is poorly resolved in experiments. A large -scale model of the apex was constructed to obtain a better insight into the flow. Surface flow visualization data indicates that the angle of attack has a strong effect on t he apex flow topology. The occurrence of primary and secondary separation is evident. At large angle of attack also tertiary separation occurs. Flowfield data generated using PIV equipment shows that the vortex core flow over the apex model is very unstead y.