亚铁氰化钠，一般为十水合物形式，化学式Na₄Fe(CN)₆·10H₂O。

亚铁氰化钠是一种柠檬黄色单斜晶系的棱形或针状结晶，溶于水，不溶于醇。在空气中易风化，在50～60 °C的条件下晶体会很快失去结晶水，在更高温度下干燥生成坚硬的块状无水盐。在常温稀酸中不分解，但在沸浓酸中分解为氢氰酸。可被氧化为铁氰化钠。强烈灼烧时分解为氰化钠、碳化铁和氮气。

Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe(CN)₆]. It is a yellow crystalline solid that is soluble in water and insoluble in alcohol. Despite the presence of the cyanide ligands, sodium ferrocyanide has low toxicity (acceptable daily intake 0–0.025 mg/kg body weight). The ferrocyanides are less toxic than many salts of cyanide, because they tend not to release free cyanide. However, like all ferrocyanide salt solutions, addition of an acid can result in the production of hydrogen cyanide gas, which is toxic. In its hydrous form, Na₄Fe(CN)₆·10H₂O (sodium ferrocyanide decahydrate), it is sometimes known as yellow prussiate of soda. The yellow color is the color of ferrocyanide anion.