Abstract Whole-cell patch-clamp recordings were used to investigate nicotinic acetylcholine receptors (nAChRs) in the human neuroblastoma cell line, SH-SY5Y. Acetylcholine, nicotine and the neuronal nAChR agonist dimethylphenylpiperazinium iodide (DMPP), but not muscarine, all evoked inward currents in the cells (voltage-clamped at −60 mV). DMPP's actions were concentration- and voltage-dependent, and were antagonised by the neuronal nAChR antagonist mecamylamine (1–3 μM). Atropine was ineffective at 0.1 μM, but at 1 μM caused significant reductions in current amplitudes. Pre-incubation of cells with 2 μM α-cobratoxin had no effect on the actions of DMPP, and inward currents could also be induced when extracellular NaCl was replaced with CaCl 2. DMPP also reversibly depolarized SH-SY5Y cells. These findings clearly identify nAChRs in SH-SY5Y cells, and provide two possible mechanisms by which receptor activation may lead to noradrenaline release, namely by triggering Ca 2+ influx through the nAChR itself or by opening voltage-gated Ca 2+ channels.