For the first time, the design of an efficient Ca-promoted cobalt/SiC catalyst for selective FTS diesel production was studied. Optimization of a mCo-nCa/b-SiC catalyst composition for producing selective synthetic diesel via Fischer-Tropsch synthesis (FTS) was carried out for the first time by both Response Surface Methodology (RSM) based on characterization and parallel bench scale FTS experimentation. Based on statistical methodologies, basicity and cobalt particle size were found to be strongly and linearly influenced by the addition of calcium and cobalt loading, respectively. Degree of reduction resulted in a non-linear dependence on the amount of cobalt supported presenting a maximum value for the catalyst containing 14.0 wt.% Co in absence of promoter. Catalytic performance demonstrated that lower cobalt contents in presence of promoter shifted C-5(+) hydrocarbon product distribution toward a more selective diesel formulation. Hence, pondering those variables that afford a compromise between CO conversion and C-5(+) selectivity, a composition of 12.5 wt.% Co with 2.0 wt.% Ca was demonstrated to be the optimum for a selective diesel production. (C) 2011 Elsevier Ltd. All rights reserved.