Pelecaniformes are large water birds feeding by hunting fish and living usually in the sea and in fresh water. Ectoparasitic lice of the genus Piagetiella are interesting from an ecological standpoint as they are found in the pouches of pelicans. Unlike chewing lice, which live on the body surface of the host, P. titan lives in the oral cavity of white pelicans (Pelecanus nocrotalus, L.). This study aimed to determine the infestation of white pelicans with P. titan in Urmia Lake, Northwest Iran, between June and August from 2004 to 2006. Sixty-two juvenile white pelicans at three different age groups of < 1 (n = 8), 1-2 (n = 23) and 3-7 (n = 31) weeks were investigated and 59 birds were found infested with lice. A total of 1637 lice were collected from the oral cavity and body of the birds, with the number of lice ranging from one to 112 per bird. P. titan were identified according to the criteria described by Price (1970), including the number of setae in various parts of body, the structures of prosternal, mesosternal and metasternal plates, the structures of female and male genitalia, presence of two ventral stout subapical setae on tibia II-III and the number of the ctenidia on femur III. This report describes P. titan on pelicans for the first time from Iran.