Preterm birth continues to pose a significant clinical dilemma and contributes to both acute and long-term neonatal morbidity. Despite efforts, the incidence of preterm birth has not decreased, partly because of our lack of understanding of the mechanisms that trigger parturition. Animal models are essential research tools for investigating the pathways that promote preterm parturition and for testing therapeutic interventions. Growing evidence correlates infection or inflammation with preterm birth. Consequently, many investigators have created animal models that reflect these findings. Current models of preterm parturition include diverse species, varying means of inducing an inflammatory or infectious state, and different routes of administration. Although each of these models can advance our knowledge, it is important to understand their advantages, disadvantages and unique characteristics. An understanding of such models will hopefully promote continued research that will ultimately lead to a decrease in preterm birth and an improvement in neonatal outcome.