This paper aims at incorporating the results of pile load tests into pile design using the Bayesian approach and assisting decision-making on the outcome of load tests. The analysis is carried out in the framework of Load and Resistance Factor Design (LRFD), since this methodology is being seriously considered to eventually replace the conventional Allowable Stress Design (ASD). The first-order, second-moment reliability method is used to develop resistance factors for pile design using statistics of the pile capacity distribution that has been updated using the Bayesian method. A criterion of minimum acceptable test outcome is proposed for assisting decision-making in load tests. To illustrate the methodology, results associated with the design method for driven piles using information from the standard penetration test (SPT) are presented. Parametric studies are performed to evaluate the effect of number of load tests and outcome of the load tests on the updated resistance factors. For the same test outcome, the Bayesian approach allows for higher resistance factors or shorter pile length than those interpreted from the ASD approach.