As physicians, we have an obligation to ensure the safety of our patients as well as to inform them of any potential risks associated with diagnostic procedures. The overall safety profile of the magnetopharmaceuticals with current FDA approval is good with regard to acute toxicity. For gadopentetate dimeglumine, toxicity. For gadopentetate dimeglumine, the agent with the greatest clinical experience, the overriding majority of adverse events consists of transient and relatively minor symptoms and reactions. Clinical trials of the newer agents reflect a similar experience but on a much smaller scale. Continued post-marketing surveillance programs should provide more information in the near future. Severe adverse reactions do occur after the administration of magnetopharmaceuticals. These often idiosyncratic and anaphylactoid reactions may cause permanent injury or death. In the two reported cases to date, the patients had a history of reactive airway disease. The incidence of severe reactions is estimated at 1 in 350,000 to 450,000 for gadopentetate dimeglumine. The rate is considerably lower than that for iodinated contrast agents, both ionic and nonionic. Magnetopharmaceuticals should be considered safe but not innocuous. The small risk must be weighed against the additional diagnostic information that is obtained with magnetopharmaceuticals. Radiologists should be aware of potential complications and have on site equipment and skilled personnel for management should an adverse event occur. The benefits to the patient of reduced morbidity and mortality from improved diagnosis with magnetopharmaceuticals will ensure continued use of current agents as well as development of additional agents.