In the crystal of the title compound, C(18)H(15)OP·0.5H(2)O, a water molecule links to two adjacent triphenylphosphine molecules by way of O-H⋯O hydrogen bonds. The crystal is twinned, the minor twin component being 36%.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.