This study aims to apply an integrated optimization approach that combines Multi-objective Optimization (MOO) and Multiple-criteria Decision-making (MCDM) to optimize a multiport mini-channel having 2D sawtooth micro fins under laminar, transitional, and turbulent flow conditions. Water was considered as working fluid. The Reynolds number (Re), fin height (Hf), fin width (Wf), the number of micro-fins in each mini-channel (N), and the distance between the successive fins (S1) were selected as design and flow parameters and the Nusselt number (Nu) and the Poiseuille number (Po) were selected as objective functions. A Genetic Algorithm based MOO study was conducted using the correlations available in the literature aiming to find the optimum values of design and flow parameters that maximize Nu and minimize Po. Then, the VIsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method was employed to help designers to select an optimum design among the Pareto optimal solution set which is the output of MOO. Finally, the optimization results obtained were compared with those obtained by the 1st Law of Thermodynamics based Performance Evaluation Criteria (PEC). The advantages and disadvantages of these methods were discussed in detail. It is revealed that the integrated approach is a more comprehensive and flexible approach that also covers the results of PEC.