In an evaluation of various 99mTc-labeled halogenated (F, Cl, Br, I) iminodiacetic acid (IDA) derivatives for hepatobiliary scintigraphy, it was found that, in the baboon model, none of these compounds performed as well as did disida. F-IDA was least effective, with the lowest biliary excretion and highest renal participation, but multihalogen substitution as in penta-F-IDA increased the biliary specificity and reduced urinary excretion to the extent that penta-F-IDA scored second to disida and even above I-IDA, with its high molecular weight. Surprising also was the relatively good performance of Cl-IDA compared to Br-IDA and I-IDA.