An empirical model of leaching of pesticides (EMOLP) was developed to simulate the concentration of fungicides throughout unsaturated soil. The model was based on chemical reactions and the travel time of a conservative tracer to represent the travel time required for water to flow between soil layers. The EMOLP was tested with experimental data of dimethomorph and pyrimethanil applied to the soil under field and laboratory conditions. The EMOLP simulated fungicide concentration on soil solids and in soil solution at different depths over time (mean square error between 2.9 mg 2 kg -2 – 61mg 2 kg -2 ) using sorption percentages instead of the coefficient of distribution and degradation rates ( k ) under laboratory conditions. The sorption process was affected by the organic carbon, clay, and the effective cation exchange capacity of the soil. The k values of dimethomorph (0.039 d -1 – 0.009 d -1 ) and pyrimethanil (0.053 d -1 – 0.004 d -1 ) decreased from 0 to 40 cm and then remained constant in deeper soil layers. Fungicide degradation was a critical input in the model at subsurface layers. The EMOLP was evaluated as a reliable mathematical tool to estimate the leachability of pesticides in tropical soil under a steady-state flow. It may be extended to other substances and soils for environmental risk assessment projects.