Intracellular calcium oscillations have fascinated scientists for decades. They provide an important cellular signal which, unlike most signalling mechanisms, is digitally encoded. While it is generally agreed that oscillations most frequently arise from cyclical release and re-uptake of intracellularly stored calcium, it is becoming increasingly clear that influx of calcium across the plasma membrane also plays a critical role in their maintenance and even in delivering their signal to the correct cellular locus. In this review we will discuss the role played by Ca(2+) entry mechanisms in Ca(2+) oscillations, and approaches to understanding the molecular nature of this Ca(2+) entry pathway.