Elementary Ca2+ signals, such as “Ca2+ puffs”, which arise from the release of Ca2+ from endoplasmic reticulum through small clusters of inositol 1,4,5-trisphosphate receptors, are the building blocks for intracellular Ca2+ signaling. The small number of release channels involved during a Ca2+ puff renders the puffs stochastic, with distributed amplitudes, durations, and frequency, well characterized experimentally. We present a stochastic model that accurately describes simultaneously the statistical properties of the duration, amplitudes, frequencies, and spatial spread with a single set of parameters.