The natural convective flow and associated heat transfer in a fluid saturated porous medium have been investigated using the generalised porous medium approach. Many new features have been predicted with the convective heal transfer boundary condition. A detailed parametric study reveals that multicellular flow patterns appear at higher Darcy and Rayleigh numbers and lower Biot numbers. Results are: presented for a Darcy number range of 10(-7) 10(-2), Rayleigh number range of 10(2)-10(9) and aspect ratios from 1 to 10.