Mazindol, 5-(p-chlorophenyl)-2,5-dihydro-3H-imidazo[2,1-a]isoindol-5-ol, has been shown to be an effective anorexic. To explore the structure-activity relationships, several 1-ethyl-3-substituted-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles were prepared and subjected to various animal screens. The 1-ethyl-3-tert-butyl-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles are capable of significantly depressing forced and spontaneous motor activity in mice but have low LD50's. Two of these compounds were tested in an Ehrlich ascites tumor screen. The 1-ethyl-3-phenyl-4-aryl-4-hydroxyindeno[1,2-c]pyrazoles depressed forced and spontaneous motor activity at low doses and were relatively nontoxic.