This paper presents the use of an artificial intel- ligence (AI) tool based on ant colony behavior to design an op- erational amplifier circuit. The ant colony optimization (ACO) is implemented in a hybrid evolutionary sizing method to automate analog circuit design. This new meta-heuristic approach that com- bines the artificial intelligence of an ant colony and the 3D matrix method is developed to determine the optimal dimensions and the main influencing performances of fundamental analog circuits and, including operational amplifiers (op-amps). The proposed methodology uses ACO and Cadence Spectre as dimensioning techniques and implementation platform, respectively. The Three Dimensions (3D) ACO algorithm is successfully used for analog circuit sizing, and the obtained results demonstrate its effective- ness in sizing basic and more complicated analog circuits.