In Tunisia, despite the activities of national programs of maternal and child health, low birth weight (LBW) remains common. The aim of this study is to draw up the epidemiological profile of the LBW in the region of Monastir and to study the chronological trends of the associated factors during a period of 14 years (1995–2008). We conducted a population study which interest 97.630 live births (from 26 to 43 weeks) in the public maternities of the region of Monastir. The mean’s age of pregnant women was 28.7±5.5 years. Among them 14.2% were aged 35 and older and 40% were primipara. Newborns were in term in 94.7% of cases. Maternal age, prenatal care, twin pregnancies and fetal complications were the factors independently associated with the occurrence of LBW in term newborns. However, only prenatal care and twin pregnancies were independently associated to LBW in preterm newborns. During the fourteenth years of the study the parturient mean age and the frequency of preterm birth increased significantly (P<0.001) while the frequency of multiparty decreased significantly (P<0.001). We found that the risk factors of LBW (advanced age, multiparty, etc.) are still common in our country and require targeted interventions.