The design of circular type cellular cofferdams is formulated as a nonlinear optimization model that takes explicit account of relevant economic and technologic aspects. The objective is minimization of total expected cost. The constraints arise from stability critera to protect against failures due to slipping of the sheet piles on the river side and interlock stresses at the joint. A solution achieved with geometric programming techniques, yields optimal cell sizes and design heights. The geometric programming approach provides important design insights by yielding the proportions of the total cost to be assigned to the cost components, fill material, sheet piling and flooding in an optimal design.