Thermohydraulic characteristics of a square minichannel heat sink with butterfly inserts are computationally analyzed for Reynolds numbers in the range 200−900 using ANSYS Fluent 2021 R1. The present study aims to discern an optimal value of pitch distance for the highest possible thermohydraulic performance, evidenced by the literature to play a vital role on heat transfer enhancement in minichannel heat sinks. Accordingly, the present study analyzes minichannel heat sinks with butterfly inserts having pitch lengths of 10mm (MCHSBTI-10), 5mm (MCHS-BTI-5), 3mm (MCHS-BTI-3), and 2mm (MCHS-BTI-2). Since introduction of butterfly inserts in minichannels enhances both Nusselt number and friction factor, Performance Evaluation Criteria (PEC), that incorporates the simultaneous effects of change in hydraulic and thermal performance, is used to assess the overall performance of the inserts, wherein a PEC value greater than unity can be considered to be adequate. Although PEC value for all the studied configurations is found to be greater than unity, the MCHS-BTI-3 configuration demonstrated the highest PEC values for the studied Reynolds number range (ranging from 1.15 − 1.78). Therefore, the optimal pitch value for the investigated geometric and flow configurations is concluded to be 3mm.