A systematic investigation of the transport properties of GdAs single crystals is presented. We report on measurements of the electric resistivity, magnetoresistance and Hall effect performed on a stoichiometric and a nonstoichiometric sample at temperatures between 1.6 and 300 K in fields up to 10 T. The stoichiometric sample behaved as a well compensated semimetal that orders antiferromagnetically, while the nonstoichiometric sample showed some anomalies that could be explained qualitatively by the model of trapped magnetic polarons. ©1996 American Institute of Physics.