Seventy-five squamous cell carcinomas of the head and neck were analysed for c-erbB-2 expression using immunohistochemical techniques with four different c-erbB-2 antibodies. No membrane staining was seen in any of the squamous cell carcinomas studied with any of the antibodies; however, c-erbB-2 cytoplasmic staining was seen in 60 per cent of the tumours. The significance of cytoplasmic staining is discussed and that it may possibly represent elevated c-erbB-2 expression in squamous cell carcinomas. C-erbB-2 cytoplasmic staining was also observed in 10 of 23 normal specimens obtained from the resection margin of the tumours. No correlations were found between positive c-erbB-2 cytoplasmic staining and any of the clinicopathological parameters or survival.