Assemblages of fish associated with exposed and sheltered sides of breakwaters and adjacent rocky reefs were sampled at coastal marinas on the north-west coast of Italy. Contrary to expectations, assemblages associated with the exposed side of artificial breakwaters did not differ from those at adjacent natural rocky reefs. Assemblages of fish associated with the sheltered side of breakwaters did, however, differ from adjacent rocky reefs and, to a lesser extent from the exposed side of the breakwaters. The internal sheltered side of marinas supported fewer species than did the external breakwaters and adjacent reefs and lacked common reef-associated species, such as Chromis chromis and Oblada melanura. In contrast, they supported greater numbers of new recruits of the sparid, Diplodus vulgaris.