The dermal sensitization potential of di-n-butylamine (CAS No. 111-92-2) was evaluated in 10 CF1(BR) mice inducted with 3 daily 0.1 mL topical applications of a 0.1% (v/v in ethanol) test solution to clipped abdomens. A group of 10 mice likewise inducted over 3 days with 0.1 mL dermal applications of 0.5% (w/v) DNCB served as the positive control. Challenge and rechallenge were administered 7 and 14 days later in .01 mL dermal applications of a 25% (v/v) solution to both dorsal and ventral surfaces of the left and right ears, respectively, of inducted test mice. The thickness of treated left ears relative to that of solvent control (ethanol) right ears indicated the degree of sensitization. One animal challenged with di-n-butylamine exhibited a positive sensitization response (20% increase in ear thickness over control) at 48-hour evaluation only. None of either test or irritation control groups had responded to challenge by the 24-hour evaluation and none responded to rechallenge. Conversely, 60% and 50% positive response in the DCNB-inducted and challenged groups at 24-hour and 48-hour evaluations, respectively, confirmed the validity of the test system.