Some unofficial sources rate the number of transsexuals in Iran to be about 150.000 (for 70 million inhabitants).

This kind of surgery is tolerated and is even encouraged since the Ayatollah Khomeini made a fatwah in that sense 25 years ago.
Homosexuality in Iran is considered a mortal sin (and thus a legal crime) while transsexuality is categorised as an illness subject to cure thanks to sex change.