Fluid flow and heat transfer over a multi-row (1-6 rows) plate-fin and tube heat exchanger are studied numerically and experimentally. Fluid flow is incompressible, three-dimensional and laminar. The effects of different geometrical parameters such as tube arrangement, tube row numbers and fin pitch (8-12 fins per inch) are investigated in detail for the Reynolds number (based on the fin spacing and the frontal velocity) ranging from 60 to 900. The average heat transfer coefficient of staggered arrangement is 15%-27% higher than that of in-lined arrangement, while the pressure drop of staggered configuration is 20%-25% higher than that of in-lined configuration. Average Nusselt number is decreased as the number of tune row is increased from 1 to 6. The number of tube row has a small effect on the average heat transfer coefficient as the row numbers became greater than 4. The numerical results for the average heat transfer coefficient and pressure drop agree well with the experimental measurements.