The authors prospectively examined the occurrence of subacute local cutaneous reactions (LCR) in patients receiving IV phenytoin over a 12-month period at a general hospital. LCR were detected in 29 of 115 patients (25.2%; 22 mild and seven moderate). All resolved within 3 weeks. Patients with LCR were older (median 68 versus 54.5 years, p = 0.004), were more likely to be in a general ward (86% versus 66%, p = 0.04), and had larger catheters (median 16 G versus 18 G, p = 0.05). The authors conclude that LCR are common in routine hospital practice, but are generally mild and benign.