The inclusion behaviour of porphyrin derivative manganese [5-(4-(carboxyphenyl-(N-L-proline)))-10-15-20-triphenylporphyrinyl] chloride 1MnCl in micellar aggregates of sodium N-dodecanoyl-L-prolinate L-SDP and of sodium dodecylsulfate SDS has been studied by means of several spectroscopic techniques. The catalytic activity in the epoxidation reaction of some test chiral olefins has been also investigated. Comparison with the case of the related manganese[5-(4-carboxyphenyl)-10-15-20-triphenylporphyrinyl] chloride 2MnCl, gave evidence that suggests the presence of a chiral functionality on the periphery of porphyrin macrocycles affects their aggregation mode within the biomembrane models. This results in the modulation of their stereoselective Cytochrome P450 biomimetic activity. © 2004 Elsevier Ltd. All rights reserved.