We have cloned human α_1C-adrenergic receptor from human prostate cDNA library. The deduced amino acid sequence of the clone (P2C4) encodes a protein of 466 amino acids that showed strong sequence homology to the previously cloned bovine α_1C-adrenergic receptor. The radioligand binding properties of P2C4 expressed in COS-7 cells were very similar to those of bovine α_1C-adrenergic receptor. With reverse-transcription polymerase chain reaction assay, we observed α_1C-adrenergic receptor transcripts in heart, brain, liver and prostate, but not in kidney, lung, adrenal, aorta and pituitary. The data show that the clone P2C4 encodes a human α_1C-adrenergic receptor cDNA, and the receptor subtype is expressed not widely but localized in several human tissues.