This paper proposes scalable conflict-free media-access protocols with a novel architecture called parallel queueing for WDM optical passive star networks. The processing and hardware resource requirements are low and the control signalling demand is significantly reduced by using a small number of parallel queues in each station. A new scheme called wormhole scheduling is introduced to compensate the relatively slow laser-filter tuning speed. The protocol using wormhole scheduling decreases the overhead of tuning (thus increases the throughput) and relieves the electronic processing bottleneck. The key ideas are: (1) to associate several parallel queues with a data channel, rather that one deep queue (as in DT-WDMA) of N static queues, N is the number of stations; and (2) to schedule multiple successive packets which are destined to the same receiver at one time. An analytical model is presented and verified through simulation. Numerical results from analysis and simulation indicate that with only 5-6 parallel queues, the protocols are capable of achieving high throughput. Thus the protocols can be scaled up for networks with a large number of stations and could lead to potential implementation.>