The biologic profiles of a hepatobiliary radiodiagnostic agent,99mTc-N/p-butylphenylcarbamoylmethyl/iminodiacetic acid,99mTc-p-butyl HIDA for short, are described in terms of its pharmacokinetics in normal rats over a 24 h period. It could be used to monitor the quality of this hepatobiliary radiopharmaceutical if prepared in an in-house hospital radiopharmacy.