In continuing search for novel celldifferentiation agents, a series of derivatives of indole-3-aceticacid and indole-3-carboxylic acid were prepared and tested against HL-60cells for their differentiation and antiproliferation activities. Among them, N-ethyl-1-benzylindole-3-carboxamide (14) was the most potent, whereas N-methyl 1-benzylindole-3-acetamide (5) and N-methyl 1-benzylindole-3-carboxamide