Low-voltage activated, voltage-operated Ca²⁺ channels are expressed in rodent male germ cells and are believed to be pivotal in induction of the acrosome reaction in mouse spermatozoa. However, in the human, very little is known about expression of voltage-operated Ca²⁺ channels in male germ cells or their function. We have used reverse transcription-polymerase chain reaction, in-situ hybridisation and patch clamp recording to investigate the expression of low-voltage activated voltage-operated Ca²⁺ channels in human male germ cells. We report that full-length transcripts for both _1G and _1H low-voltage activated channel subunits are expressed in human testis. Multiple isoforms of _1G are present in the testis and at least two isoforms of _1H, including a splice variant not previously described in the human. Transcripts for all the isoforms of both _1G and _1H were detected by reverse transcription-polymerase chain reaction on mRNA isolated from human spermatogenic cells. In situ hybridisation for _1G and _1H localised transcripts both in germ cells and in other cell types in the testis. Within the semeniferous tubules a1H was detected primarily in germ cells. Using the whole cell patch clamp technique we detected T-type voltage-operated Ca²⁺ channel currents in isolated human male germ cells, though the current amplitude and frequency of occurrence were low in comparison to the occurrence of T-currents in murine male germ cells. We conclude that low-voltage activated voltage-operated Ca²⁺ channels are expressed in cells of the human male germ line.