An electrolytic technique for growing rutile is described. The crystals obtained show n-type electrical conductivity. The defect structure was studied by EPR. The behavior of the conductivity and the changes in the defect structure as a result of heat-treatment in an oxidizing atmosphere shows the as-grown crystals to be oxygen deficient. An EPR spectrum of Pt3+ in rutile is reported for the first time and a spectrum previously attributed to substitutional Tis3+ is confirmed as such. © 1976, The Electrochemical Society, Inc. All rights reserved.