A magnetic‐susceptibility study of the Magne´li phases of the titanium‐oxygen system shows an anomalous dependence on the stoichiometry. The magnetic susceptibility has been fitted (where applicable) to a Curie‐Weiss law of the form &khgr; =C/(T+&thgr;) +A, using a least‐squares analysis. The Curie constantCincreases with increasing stoichiometry despite the apparent increasing magnetic dilution (addition of Ti4+ions) of the Ti3+ions. Some of these phases exhibit an antiferromagnetism; others show an apparent paramagnetic behavior; and several show semiconductor‐to‐metal transitions.