IntroductionThere is a paucity of information on utilisation of emergency medical services in Nigeria. This study was conducted to determine the pattern of respiratory diseases seen among adults in an emergency room(ER) and their mortality within twenty- four hours in a health facility in Nigeria.MethodsWe carried out a retrospective study on adult patients that presented with respiratory condition from November 2004 to December 2010 at the emergency room of Federal Medical Centre Ido-Ekiti, south western, Nigeria.ResultsA total of 3671 cases were seen, 368 were respiratory cases accounting for 10.2 % of the total emergency room visitations. The male to female patients ratio was 1.2:1 and their mean was 49 9 ± 20.3 years. Pneumonia (34.5%) was the most common cases seen in the ER, followed PTB (29.4%), acute asthma (24.5%) , acute exacerbation of COPD (10.3%), upper airway tract obstruction and malignant pleural effusion were 0.5% respectively. Fourteen of the PTB cases (3.8%) were complicated by cor-pulmonale, 9(2.5%) by pleural effusion, 4(1.1%) by massive haemoptysis and 2(0.5%) by pneumothorax. Twenty-four hours mortality was 7.4% and 44.4% of the death was due to PTB, 37.0% was due to pneumonia and 14.8% due to acute asthma attack. The overall mortalities also had a bimodal age group distribution as the highest death was recorded in ages 30-39 and ≥70 years.ConclusionPneumonia and PTB were the leading respiratory diseases among adults causing of emergency room visit and early mortality in this health facility in Nigeria.