Geometric Programming is a new technique developed to solve nonlinear engineering design problems including linear or nonlinear constraints. This paper illustrates the use of Geometric Programming in obtaining optimal design parameters for a class of welded beam structures. The procedure is illustrated through the solution of a particular welded beam design formulation. In G/P format the problem solved consists of 9 nonlinear constraints, 24 terms, 7 variables, with 16 degrees of difficulty and a nonlinear objective function. Geometric Programming is compared to several other solution techniques, and found to be very efficient. Computational experience suggests that other problems of this class may be solved with similar efficiency. The welded beam problem given is a real world design situation typical of many encountered in actual practice. The solution is given for the first time in this paper.