An optimization of flow conditions is presented to minimize permeate product cost in ultrafiltration in laminar channel flow. The methodology for the pressuredriven membrane system is based on a hydrodynamic optimization scheme developed by Sonin and Isaacson for electrochemical systems. Experimental data are presented for permeate flux as a function of transmembrane pressure for the ultrafiltration of bovine serum albumin solution in laminar channel flow with and without detached strip-type turbulence promoters. Empirical expressions are established for the limiting permeate fluxes as a function of the flow rate and interpromoter spacing. Applying the economic optimization scheme, the performance characteristics of the convection-promoted systems are assessed. The optimum values for the interpromoter spacing, the permeate flux, and the Reynolds number are also determined.