Aromatase (P450 arom) is a target of pharmacological interest for the treatment of breast cancer. New series of 7-(α-azolylbenzyl)-1H-indoles and indolines were synthesized as non- steroidal inhibitors of P450 arom. Selectivity was studied towards P450 17α enzyme. The most active compound, 1-ethyl-7-[(imidazol-1-yl)(4-chlorophenyl) methyl]-1H-indole 12c exhibited promising relative potency (rp) of 336 (rp of aminoglutethimide= 1) and most of ...