The pharmacokinetics of PTT-119, a new alkylating agent, was studied in 8 advanced cancer patients. PTT-119 disappeared rapidly from plasma after administration at a dose of 3 mg/kg by i.v. bolus injection. The HPLC method shows plasma levels of m-bis (dichloroethyl)amino-phenyl-L-alanine which is the major metabolite of PPT-119. Elimination of the drug from plasma can be described by a one-compartment model. Mean values of 77.8 min for the half-life, 510.8 ml/min for the total plasma clearance and 0.69 l/kg for the volume of distribution were found.