Four hundred and twelve and 408 participants received amoxicillin thrice or twice daily, respectively. Treatment failure was detected in 94 (22.8%) and 94 (23.0%) patients in intention-to-treat analysis (risk difference 0.2%; 95% CI: −5.5%–6.0%) and in 80 (20.1%) and 85 (21.3%) patients in per-protocol analysis (risk difference 1.2%; 95% CI: −4.4%–6.8%). Pneumonia was radiologically confirmed by concordant reading in 277 (33.8%) cases, among whom treatment failure was registered in 25/133 (18.8%) and 27/144 (18.8%) participants from the thrice and twice daily doses subgroups, respectively (risk difference −0.05%; 95% CI: −9.3%–9.2%).