On allowing SnPh3OH to react with Ph3AsO, the adduct SnPh3OH.Ph3AsO·H2O is obtained, its infrared and Mössbauer studies carried out. The coordination of Ph3AsO to the tin (IV) centre leads to an infinite chain structure containing a trans bipyramidal trigonal SnC3O2 arrangement with OH and Ph3AsO being in apical positions. The water molecule bridges through hydrogen bonds the Lewis base and SnPh3OH