Resumo. This study aimed to develop diameter increment models for individual trees of Araucaria angustifolia. Were used measurements of 262 araucaria individuals sampled in the permanent plots of the Project PELD - CNPq. Using correlation analysis, covariance and regression, increment models were adjusted, stratified by diameter class, variable with the highest correlation with the increase in diameter. We used the annual periodic increment, calculated based on the diameter increment of the individuals in the analyzed period. Models resulted in good estimates of the increase, however, showed wastes with a strong tendency.