The aim of this research work was to determine the enthalpy of fusion of naphthalene from the freezing point Curves. Naphthalene and diphenylamine were mixed in various proportions. A mixture of pure naphthalene and diphenylamine were melted in Beckmann’s Freezing point apparatus packed with crushed ice. The temperatures of the melted samples were taken at an interval of 30seconds until a constant temperature (freezing point) was maintained. A curve of temperature against time and a graph of logarithm of mole fractions against reciprocal of freezing point temperatures of the various mixtures were plotted. The freezing point and enthalpy of fusion of naphthalene obtained were found to be 790C and 18833.7Jmol-1(35.1669Calg-1) respectively. These values closely agreed with 800C and 152Jg-1 (36.0Calg-1) as reported by McGlashan.