Department of Chemistry, Regional Engineering College, Rourkela Manuscript received 5 August 1974, accepted 24 July 1975 The complex formation of dimethyl tin with the citrate ligand has been studied by the pH titration method. The formation of a 1 : 1 type of complex is reported. A neutral complex (C) is formed below \(p\)H 3.4 which behaves like a tribasic acid and dissociates to complexes Cl-, C\(_2^-\) and C\(_3^{2-}\)and protons at higher \(p\)H. The equilibrium constants of the reactions, (CH3)2Sn++\(+\)H3Cit.\(\rightleftharpoons\)C+2H+, C\(\rightleftharpoons\)C\(_1^-\)+H+, C\(_1^-\)\(\rightleftharpoons\)C\(_2^-\)+H+ and C\(_2^-\)\(\rightleftharpoons\)C\(_3^{2-}\)\(+\)H+ are found to be 2.29 x 10-3, 6.31 x 10-5, 5.48 x 10-6 and 5.28 x 10-8 respectively.