Telephone scatologia is the making of obscene telephone calls for sexual pleasure. It is usually classed as a paraphilia from a medical viewpoint, although from the viewpoint of the recipient of the calls, and of the law, it is generally considered to be a form of sexual harassment.

Obscene phone calls exploit the potential of the telephone system for real or apparent anonymous communication. It is generally believed that the callers want the attention of their victims, and in some cases are willing to frighten them to get attention.

The advent of caller ID has greatly reduced the number of obscene phone calls.

Generally, recipients of obscene phone calls are advised to simply put the telephone down on obscene callers, and to report their caller ID to the police. If caller ID is not available, they should still report the call to the police; in the event of repeated or extreme cases, the police will get the telephone company to reveal the true calling number, which is logged by the telephone company computers, regardless of caller ID settings, and stored for at least a complete billing cycle (and far longer in most jurisdictions).