The safety and efficacy of the MRI contrast medium gadodiamide injection (OMNISCAN) in children is summarised. Four open and three double-blind, multinational, multicentre comparative trials have been undertaken. Overall, 353 patients (15 days to 18 years, plus one 21 years) received gadodiamide injection, and 128 (2-18 years) received gadopentetate dimeglumine (Magnevist), intravenously at 0.1 mmol/kg body weight, to aid the identification of CNS and body lesions. Adverse events were reported in 13 (4%) patients given gadodiamide injection and 8 (6%) given gadopentetate dimeglumine; few patients reported injection-associated discomfort. The post-contrast scan gave more diagnostic information in 223 (63%) patients given gadodiamide injection (CNS and body indications). In the comparative trials, the post-contrast scan gave more diagnostic information for 91 (65%) and 82 (64%) patients given gadodiamide injection and gadopentetate dimeglumine, respectively (CNS indications only). Gadodiamide injection (0.1 mmol/kg body weight) was safe and effective in infants, children and adolescents.