A B C Z. Naturforsch. 69a, 195 – 198 (2014)doi:10.5560/ZNA.2014-0008Invariance, Conservation Laws, and Exact Solutions of the Nonlinear Cylindrical Fin Equation1 Department of Mathematics and Statistics, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia2 School of Mathematics, Centre for Differential Equations Continuum Mechanics and Applications University of the Witwatersrand Johannesburg, Wits 2050, South AfricaReceived August 6, 2013 / revised January 6, 2014 / published online April 2, 2014Reprint requests to: A. H. K.; E-mail: abdul.kara@wits.ac.zaFins are heat exchange surfaces which are used widely in industry. The partial differential equation arising from heat transfer in a fin of cylindrical shape with temperature dependent thermal diffusivity are studied. The method of multipliers and invariance of the differential equations is employed to obtain conservation laws and perform double reduction.Key words: Nonlinear Cylindrical Fin Equation; Exact Solutions; Conservation Laws.