Background:One of the infectious diseases which is the main cause of the high infant mortality rate in the world is pneumonia. Many factors can increase the incidence of pneumonia in children under 4 years old, including mothers' knowledge and attitudes about parenting and the existence of family members who smoke, the number of family members who smoke, and smoking areas of family members who smoke (exposure to cigarette smoke). Purpose: The purpose of this study was to analyze differences in pneumonia risk based on parenting and exposure to cigarette smoke in children under 4 years. Method: This study used a case control study design with 50 respondents using a ratio of 1: 4 (10 cases and 40 controls). Case criteria are children under 4 years of age who have been diagnosed with pneumonia by a doctor or paramedic in April-May 2018 and control criteria are children under 4 years old who have not been diagnosed with pneumonia or other diseases by a doctor or paramedics. The research was carried out by Bulak Banteng Health Center in April-May 2018 with interviews using a questionnaire. Data analysis was performed by univariate and bivariate analysis using the Chi Square test. Results: The results showed that smoking places had the greatest difference in the risk of pneumonia in children under 4 years (44.62%), while the other factors ranked from the largest RD were knowledge of health practices at home (32%), the presence of family members who smoked ( 27.3%), the number of family members who smoke (20% 5), and the attitude of health practice at home (9.6%). Conclusion: The biggest risk difference (RD) for the incidence of pneumonia in children 0-4 years old is the smoking place variable of family members who smoke, then followed by the variable knowledge of health practices at home, the presence of family members who smoke, the number of family members who smoke, and who have risks the smallest is the attitude of the mother in the practice of health at home. bahwa tempat merokok memiliki perbedaan besar risiko pneumonia pada anak dibawah 4 tahun terbesar (44,62%), sedangkan faktor lainnya diurutkan dari RD terbesar yaitu pengetahuan praktik kesehatan di rumah (32%), keberadaan anggota keluarga yang merokok (27,3%), jumlah anggota keluarga yang merokok (20%5), dan sikap praktik kesehatan di rumah (9,6%). Kesimpulan: Perbedaan risiko (RD) terbesar untuk kejadian pneumonia anak 0-4 tahun adalah variabel tempat merokok anggota keluarga yang merokok, kemudian diikuti variabel pengetahuan praktik kesehatan di rumah, keberadaan anggota keluarga yang merokok, jumlah anggota keluarga yang merokok, dan yang memiliki risiko terkecil adalah sikap ibu dalam praktik kesehatan di rumah.