Koro is a clinical syndrome characterized by the conviction of penile
retraction and fear of inevitable death upon its disappearance into th
e abdomen. The syndrome is generally considered culture bound, yet an
increasing number of sporadic cases were attributed to psychiatric, sy
stemic or neurologic pathology. in the following article, sporadic kor
o cases associated with paranoid psychosis or schizophrenia have been
assembled, indicating that immigration is an important factor in the p
athogenesis of the clinical phenomenon. The interplay between psychosi
s, transculturation and cultural influence affecting koro development
is discussed.