From a survey on studies on convective heat transfer in microchannels. the Brinkman number is proposed as a parameter for correlating the convective heat transfer parameters in microchannels. The proposal emerges from a dimensional analysis of the variables influencing the laminar forced convection in microchannels and it can explain the unusual behaviour of convective heat transfer in the laminar regime in microchannels. Its incorporation is also supported by an energy balance across the microchannel. The physical significance of the Brinkman number as applicable to microchannels and the role played in convective heat transfer in microchannels are elaborated. The limited experimental data reported in the literature for the laminar regime heat transfer seem to correlate with the number. A dimensionless geometric parameter is also proposed.