Introduction. Foreign body aspiration is an emergency condition and may be fatal. Delayed diagnosis and treatment may be associated with complications. This study evaluated the association between time until treatment and complications due to foreign body aspiration. Methods. This study was a retrospective study conducted at Khon Kaen University Hospital, Thailand. We enrolled patients diagnosed with foreign body aspiration with evidence of foreign body detected using direct laryngobronchoscopy at any area from the larynx to the bronchus. Descriptive statistics were used to analyze the association of times of treatment with complications of foreign body aspiration. Results. During the study period, there were 43 patients that met the study criteria. The most common age group was 0–2 years. Plant seeds were the most common foreign bodies (41.9%), and the right main bronchus was the most common site (16 patients, 37.2%). There were 30 patients (69.8%) that experienced complications from foreign body aspiration. Pneumonia was the most common complication (14 patients, 32.6%). The retention time was not significantly associated with the presence of complications (p value: 0.366). Two patients (4.7%) died due to complete airway obstruction and prolonged hypoxia. Conclusion. Times until treatment were not significantly associated with complications from foreign body aspiration.