The beneficial effects of synthetic conditioners such as broadleaf-4 (BL-4) on soil physical properties are well established, but their effects on soil chemical properties are still controversial. Elemental Sulfur (S) has been used extensively to reduce soil pH and alleviate nutrient deficiency of calcareous soils, but its effect is unpredictable and in some cases failed to produce the desired results. Little information is available on the combined effects of synthetic conditioners and elemental sulfur on physical and chemical properties of calcareous soils. A laboratory study in stratified columns was conducted on two calcareous soils varying in texture and CaCO3 content for 16 weeks. Air-dried soil samples were packed to 1.50 (sand), and 1.44 Mg m-3 (loamy sand) bulk density into 50-cm columns. The top layer (5-cm) of soil from each column was removed and amended with S at rates sufficient to neutralize 0.0, 10, 20, and 40% of the Ca CO3 of each soil, and later on mixed with four concentrations of BL-4 i.e. 0.0, 0.2, 0.4 and 0.6% on dry weight basis. In both soils, addition of S and/or BL-4 significantly affected some soil physical properties such as water content at field capacity, soil expansion, and bulk density of the treated layers. The order of effectiveness of the treatments was BL-4 > S+BL-4 > S > control. However, the addition of BL-4 alone adversely affected the soil chemical properties such as an increase in pH, soluble Na and decrease in soluble Ca, Mg, and some extractable micronutrients. The application of BL-4 combined with S showed significant beneficial effects on the physical and chemical properties of the treated soils. The order of increase was S+BL-4 > S > control. Overall, combined application of S and BL-4 showed considerable beneficial effects on the physical and chemical properties of both soils.