Community-acquired pneumonia is complicated by purulent pleural effusion in approximately 28% of affected children. Its incidence has increased over the last decade. Streptococcus pneumoniae is the most frequent causal microorganism, encountered in roughly 80% of cases. We report the case of an immunocompetent 13-year-old teenager wearing orthodontic braces who suffered from pleuropneumonia due to Capnocytophaga sputigena. To date, this Gram-negative bacillus, a commensal of the buccal cavity, had never been reported to be responsible for pleural or lung infection. The clinical presentation is similar to that observed with usual bacteria, while bacterial sensitivity to betalactam antibiotics is excellent.