PACSIN 1, which is mainly detected in brain tissue, is one of the PACSIN-family proteins involved in endocytosis and recruitment of synaptic vesicles. It binds to dynamin, synaptojanin 1 and N-WASP, and functions in vesicle formation and transport. However, the mechanisms of action of PACSIN 1 in these processes are largely unknown. Here, full-length and five C-terminal truncation constructs of human PACSIN 1 have been successfully expressed and purified in Escherichia coli. PACSIN 1 (1-344) was crystallized and diffracted to a resolution of 3.0 A. The crystal belonged to space group C2, with unit-cell parameters a = 158.65, b = 87.38, c = 91.76 A, alpha = 90.00, beta = 113.61, gamma = 90.00 degrees . There were two molecules in the asymmetric unit and the solvent content was estimated to be about 70.47%.