K-struvite (potassium magnesium phosphate, KMgPO₄.6H₂O) is a promising multinutrient slow-release fertilizer; however, it may contain cadmium (Cd) in significant ranges like other phosphorus (P) fertilizers. This paper focuses on dissolution of a synthesized K-struvite in water, acid solutions and complexing agents. Firstly, K-struvite was synthesized by using Cd containing phosphoric acid (H₃PO₄). After its characterization, a three-stage dissolution study was carried out. The release of nutrient elements and Cd into extracts was studied. Phosphorus (P) and potassium (K) solubilities in pure water are low, not more than about 2.5% at the end of three extractions. It was found that solubility increased with the presence of mineral and organic acids. The presence of complexing agents also enhanced the dissolution of K-struvite. At the end of three extractions, citric acid (CA, C₆H₈O₇.H₂O) solution solubilized P about 38%, while dissolved K was about 35%, in cumulative. In the case of 0.001 mol/L Na₂EDTA (C₁₀H₁₄N₂Na₂O₈.2H₂O), the solubilized K-struvite was found to be about 40%, which was about 14% in a 250 mg/L Na-humate. The maximum concentrations of Cd in the third extracts of hydrochloric acid (HCl), CA, oxalic acid (OA, C₂H₂O₄) and Na₂EDTA were measured to be in the range of about 14–19 μg/L, which corresponds to a Cd solubilization more than 46% for the three successive extractions.