Visual surveys along subtidal belt transects were used to compare fish assemblages on an experimental and a control site before and after the removal of a canopy-forming kelp forest. The giant kelp Macrocystis pyrifera (L.) C.A. Agardh was removed at the holdfast from approximately equals 1 ha of high relief structurally complex rock substratum. The abundance of seven species of fish, of which five were considered midwater species, significantly declined after the kelp was removed. Results indicate that the presence of a giant kelp forest may increase the abundance and species diversity of the fish assemblages over a high relief rocky reef in central California, U.S.A.