The present invention relates to a cosmetic or dermatological composition containing a continuous aqueous phase in which are dispersed vesicles based on at least one alkyl polypentoside, and also comprising at least one alcohol and at least one surfactant.More precisely, the cosmetic or dermatological composition comprises at least one cosmetic or dermatological active agent and at least one continuous aqueous phase in which are dispersed vesicles, said vesicles comprising at least one alkyl polypentoside obtained by reaction of a pentose and of at least a first and a second fatty alcohol comprising a different number of carbon atoms ranging from 10 to 12, said polypentoside having an average polymerization degree of less than or equal to 2, and said composition also comprising at least one surfactant having a HLB of less than 10, and at least one alcohol containing from 1 to 5 carbon atoms. The present invention also relates to a process for preparing the composition, which consists in placing a mixture comprising alkyl polypentoside, the surfactant and the alcohol in contact with an aqueous phase with stirring.