Electron‐paramagnetic‐resonance (EPR) has been used to investigate point defects in a single crystal of as‐grown CdGeAs2. Spectra taken at 17 K with the magnetic field parallel to thecaxis show a broad signal (∼165 Gauss wide) centered ongc=2.018 and a sharper signal (∼56 G wide) centered ongc=2.015. Together, these signals represent an unpaired‐spin concentration of approximately 5×1019cm−3. A single broad signal (∼165 G wide) centered onga=1.995 is observed at 17 K when the magnetic field is along theaaxis. It is suggested that these dominant EPR‐active defects in CdGeAs2consist of either a cation vacancy or an antisite cation with the unpaired spin shared by the four neighboring As ions. Additional weak EPR lines appear when the temperature is increased (from 17 to 40 K) and the microwave power is decreased (from 7 to 2.3 mW). ©1995 American Institute of Physics.