Introduction: more than 20 million infants were born with low birth weight in worldwide. Low birth weight contributes more than 80 percent of all the neonatal mortality. In Ethiopia, studies have shown that there is a high prevalence of low birth weight among newborns. Thus, this study was aimed to determine the magnitude and associated factors with low birth weight among newborns delivered at term in Kambata-Tembaro zone, Southern Ethiopia, 2018.

Methods: institution based cross-sectional study design was used. The sample size was proportionally allocated to each hospital. The total of 341 study participants was enrolled using systematic random sampling techniques. Data were collected by interview-administered questionnaire and entered using Epi-Info version-7 and exported to SPSS version 20 for analysis. Multivariate logistic regression analysis was carried out to identify associated factors with the low birth weight.

Results: the prevalence of low birth weight was 18% and significantly associated with the mothers’ non-employment [aOR=5.4;95%CI:1.7-17.4], residing in the rural [AOR=5.4; 95%CI:2.1-14.7], unintended pregnancy [aOR=2.0;95%CI:1.2-3.8], not attending antenatal care [aOR=2.3;95%CI: 1.3-2.7], mothers with greater than three births [aOR=1.5;95% CI:1.8-2.6], birth interval less than or equal to two years [aOR=1.9;95%CI:1.6-3.6] and intimate partner violence during pregnancy [aOR=2.1:95% CI: 1.1-3.9].

Conclusion: the study finding shown that the prevalence of low birth weight among newborn was high (18%) in the study. Preventing of low birth weight is an important intervention to reduce neonatal death. Therefore, maximizing women economic status, providing quality family planning services, enabling pregnant women to use antenatal care and preventing intimate partner violence during pregnancy via launching women empowering strategies in the community level is highly recommend.