I develop a model of nonstationary relational contracts in order to study internal wage dynamics. Workers are heterogeneous, and each worker’s ability is both private information and fixed for all time. Learning therefore occurs within employment relationships. The inferences, however, are confounded by moral hazard. Incentive provision is restricted by an inability to commit to long-term contracts. Relational contracts, which must be self-enforcing, must therefore be used. The wage dynamics in the optimal contract, which are pinned down by the tension between incentive provision and contractual enforcement, are intimately related to the learning effect.