Background: Pneumonia is an infectious disease which is the main killer among children under five. This study aims to analyze socio-economic and environmental determinants of the incidence of pneumonia in children under five after the earthquake.  Subjects and Method: This study used observational analytic using case control. The total sample of 237 children under five aged 12-59 months old and the sampling technique was fixed disease sampling. The independent variables in this study were birth weight, exclusive breastfeeding, nutritional status, immunization status, maternal education, family income, healthy behavior, physical quality of the house, exposure to cooking fuel smoke, smoking activities of family members and active village influences. Collecting the variables was through questionnaires and analyzed by using path analysis.  Results: Birth weight (b=-1.92; 95%CI=-3.35 to -0.51; p=0.008), exclusive breastfeeding (b=1.41; 95%CI=-2.43 to -0.38; p=0.007), nutritional status (b=-2.98; 95%CI=-4.10 to -1.87; p<0.001), immunization status (b=-1.46; 95%CI=-2.51 to 0.40; p=0.007), maternal education (b=-1.46; 95%CI= -2.63to -0.28; p=0.014), family income (b=-1.86; 95%CI=-3.32 to-0.41; p=0.012), healthy behavior (b=-1.25; 95%CI=-2.28 to -0.21; p=0.018), physical quality of the house (b=-1.16; 95%CI= 2.21 to -0.12; p=0.030), and active standby village strata (b=-1.25; 95%CI=-2.49 to 0.01; p=0.048) can reduce the incidence of pneumonia in children under five. Smoking activities of family members (b=1.38; 95%CI=0.02 to 2.73; p=0.045) and exposure to cooking fuel smoke (b=1.43; 95%CI=0.35 to 2.51; p=0.010) can increase the incidence of pneumonia in children under five.   Conclusion: The decrease in the incidence of pneumonia was influenced directly by healthy behavior, immunization status, nutritional status, physical quality of the house, exclusive breastfeeding, birth weight, and active standby village strata. Family smoking activities and smoke exposure to cooking fuel can increase the incidence of pneumonia in children under five.  Keywords: Pneumonia, socioeconomic, after earthquake, path analysis