Pneumonia remains the leading cause of mortality in children under five outside the neonatal period. Progress has slowed down in the last decade and increased efforts to scale-up effective pneumonia interventions are needed. We used the Lives Saved Tool (LiST), a modelling software for child mortality in low- and middle-income settings, to prospectively analyse the potential impact of upscaling pneumonia interventions in Bangladesh, Chad, and Ethiopia from 2023-2030. Haemophilus influenzae type B (Hib) vaccination, pneumococcal conjugate vaccine (PCV), oral antibiotics, pulse oximetry and oxygen were included as pneumonia interventions in our analysis. Outcomes were number of pneumonia deaths averted, proportion of deaths averted by intervention, and changes in the under-five mortality rate. Our results show that 19,775 lives of children under five could be saved in Bangladesh, 76,470 in Chad, and 97,343 in Ethiopia by scaling intervention coverages to ≥90% by 2030. Our estimated reductions in pneumonia deaths among children under five range from 44.61% to 57.91% in the respective countries. Increased coverage of oral antibiotics, pulse oximetry, and oxygen show similar effects in all three countries, averting between 18.80% and 23.65% of expected pneumonia deaths. Scaling-up PCV has a prominent effect, especially in Chad where it could avert 14.04% of expected pneumonia deaths. Under-five mortality could be reduced by 1.42/1000, live births in Bangladesh, 22.52/1000, in Chad, and 5.48/1000, in Ethiopia. This analysis shows the high impact of upscaling pneumonia interventions. The lack of data regarding coverage indicators is a barrier for further research, as well as policy and implementation, all requiring increased attention.