The stability of dopamine hydrochloride (Intropin) in several large-volume parenteral solutions was studied. Admixtures of dopamine were assayed by colorimetric and chromatographic procedures. Admixtures (800 mug dopamine per ml) in the following intravenous fluids in glass bottles at pH 6.85 or below were found to be chemically and physically stable for at least 48 hours at room temperature: dextrose 5%, dextrose 5% and sodium chloride 0.9%, 5% dextrose in 0.45% sodium chloride, dextrose 5% in lactated Ringer's solution, lactated Ringer's injection, 0.9% sodium chloride, 1/6 molar sodium lactate, and 20% mannitol. The admixture of dopamine in 5% dextrose was stable for a minimum of seven days at 5 C. A 5% dextrose-dopamine admixture in a polyvinylchloride bag was stable for at least 24 hours at room temperature. The admixture of dopamine in 5% sodium bicarbonate solution produced an unstable solution of pH 8.20. A chemical and physical change (development of a pink color) was observed in this admixture. It is recommended that dopamine not be added to 5% sodium bicarbonate solution or any alkaline intravenous solution.