The Canadian Certified Reference Materials Project announces recommended values for radium‐226 activity in four reference materials previously certified for uranium. Thirteen laboratories participated in the interlaboratory program for DL‐la, DH‐la, BL‐4a and BL‐5. Four measurement techniques were applied. Procedural and instrument calibrations were performed with certified radium solutions from the National Bureau of Standards, thereby establishing traceability of the recommended values for radium‐226 in DL‐la, DH‐la, BL‐4a and BL‐5. These reference ores are also shown to be close to, if not in, radi