Thirty-one rice soils from different locations in the Philippines were incubated anaerobically for 100 d to determine methane (CH4) production potentials and to establish relationships between physico-chemical properties of soil and CH4 production potential. These soils showed pronounced variations in pattern and magnitude of CH4 production. Total CH4 production over 100 d incubation ranged from 163 to 837 μg CH4 g−1 soil. Total N, soil texture (clay and sand fractions mainly) and cation exchange capacity (CEC) of the soils had significant effect on CH4 production potential. Available K and active Fe content also affected the CH4 production potentials of various soils. An assessment of CH4 production with high accuracy could be obtained from soil redox potential (Eh) development during incubation; the difference between initial and equilibrium Eh allowed a computation of CH4 production with more than 70% reliability. The CH4 production potentials obtained over long incubation periods could be assessed, with reasonable accuracy, by a relatively short incubation experiments and fewer measurements of CH4 production. Only three samplings of CH4 production rate within a short incubation period of 37 d facilitated a prediction of total CH4 production over 100 d incubation using the following algorithm:P0-100=99.21+10.79X4+11.69X16+45.79X37 (R2=0.91; P<0.01),where P0-100 is the total CH4 production during 100 d of incubation and Xn is CH4 production rate at n days of incubation. Longer incubation periods (86 d) were required to achieve a reliability of more than 95%.