Four phenothiazinederivatives containing the bis(beta-chloroethyl)aminopropyl side chain were prepared and evaluated in the murine L-1210, P-388, and B-16 melanoma intraperitoneal tumor systems. Moderate P-388 activity was observed. An aminoethyl phenothiazinemustard was compared with the aminopropyl analogs and was superior in all test systems. None of the compounds tested against the murine ependymoblastoma