General aspects of the influence of mass transport phenomena in micellar multiphase systems are discussed and demonstrated on the example of the hydroformylation of a long-chain olefin. The dispersion state of the multiphase system was characterized to identify the occurring mass transport processes. Therefore, images were taken with an endoscopic technique and combined with conductivity measurements. Subsequently schematic concentration profiles were derived by with help of k(l)a value measurements in order to explain the occurring mass transfer processes. The influence of mass transport limitations on the hydroformylation reaction was estimated by kinetic measurements with varying stirrer rotation frequencies.