Abstract A novel alternating offset oblique microchannel (AOOMC) is proposed aimed at enhancing the thermal–hydraulic performance (THP) in microchannels. 3-D, conjugate numerical simulations are carried out over a range of Reynolds number from 200 to 800. The effect of three geometric parameters, relative oblique channel width relative fin offset width and oblique angle on THP is evaluated. THP shows an increasing–decreasing trend with and increases with increase in and for the range tested. The optimal geometry, and showcases the highest THP of 2.41 at Re = 800 which is superior to other enhanced microchannel geometries from the literature.