The development of the personal computer and its mass storage capabilities has enabled long-term digitization of voltage records at high sampling rates. This paper presents a program that employs algorithms to analyze a sampled record for spontaneously occurring events. A detection algorithm employs amplitude and temporal parameters to identify the onsets of these events. Other algorithms then characterize size and shape features of these events. Examples of the results of these algorithms are given for intracellularly recorded excitatory postsynaptic potentials (EPSPs). These algorithms permit rapid and accurate quantitation of tens of thousands of events that may occur over many minutes. It is suggested that this set of algorithms may be applied to biological events other than synaptic potentials.