Background and Objectives: The complications of preterm birth constitute the most common causes of death in infants. The purpose of this study was to identify maternal risk factors contributing to preterm birth.

Materials and Methods: This was an analytical research (case-control) which was carried out in 2010 in Shohada Hospital in Quchan. The questionnaires were completed via personal interviews and the collected data were analyzed (CI: 95%) with SPSS v.17 statistical software using descriptive analyze.

Result: The results indicated that the most frequent risk factors for preterm birth were multiparity (25%), PROM (8.3%), preeclampsia (8.3%) and renal diseases (6.7%).

Conclusions: According to the results of this study, devoting more attempts to promoting the quality and quantity of mothers' information about the risk factors of preterm infant birth and emphasizing the pre- pregnancy and during pregnancy cares can play a significant role in reducing the birth of preterm infants.

Keywords: Infant, Preterm, premature