A method for the determination of cobalt in 18/8 steels, based on formation of ^60mCo is proposed. Most of the iron is extracted, then cobalt is extracted as its α-nitroso-β-naphtol complex into toluene. The losses are determined exactly. A determination is complete within 2 h with a precision of ±9%; the limit of sensitivity is 2 μg of cobalt. The results obtained (average 350 p.p.m.) are compared with results obtained spectrophotometrically (average 368 p.p.m.).