Acid sulfate soils have a high agricultural potential if reclaimed by suitable amendments. The objectives of the simulated study were to evaluate the use of basic slag (10 and 20 MG/ha) and groundwater depth (0 and 50 cm below soil surface) as physico-chemical amendments of acid sulfate soils (Salidic Sulfaquept and Typic Sulfic Halaquept) for economical production of rice (Oryza sativa, L. cv. BR 3). A randomized complete block design in a 2 x 2 x 2 factorial arrangement was laid-out with 3 replications for each treatment combination. Basic slag was incorporated during soil puddling. N, P and K were applied at 100, 60 and 40 kg/ha, respectively. Thirty day-old rice seedlings were transplanted at 4 plants/hill with a 15 cm distance between hills, and were allowed to grow until harvest. Results of pre- and post amended soil analysis have shown that interactive effects of 20 MG basic slag/ha and 50 cm groundwater depth have significantly increased pH, calcium (25%), magnesium (>28%), and potassium (2%) concentration, and base-exchange capacity (53%) with an associated decreased in sodium (2%), iron (5%), and aluminum (>39%) concentration of soils over time. Soil pH increased quadratically in response to interactive effects of basic slag and groundwater depth. However, the simple effects of both basic slag (41 vs. 3%) and groundwater depth (54 and 9%) were equally consistent as their interactive effect on yield and harvest index (54 vs. 3%) of rice.