Different micellar systems are characterized. Hydroformylation reactions are carried out in the most appropriate ones and are compared with hydroformylations in a non-micellar system. Reaction rates and selectivities for aldehydes are higher than the micelles. In addition to this, olefins between C-6 and C-16 are successfully hydroformylated in the micellar system, whereas Cg is the highest olefin that can be hydroformylated without micelles. The behavior of the reaction in the micellar system is very sensitive to the initial composition and reaction conditions.