Oxygen may cause serious consequences when administered wrongly. This study aimed to assess doctors' and nurses' knowledge of acute oxygen therapy and perceived delivery barriers. Participants and Methods: We conducted a cross sectional study among 202 healthcare providers (134 doctors and 68 nurses) in a Nigerian hospital. The validated Acute Oxygen Therapy Questionnaire (AOTQ), which consisted of 21 knowledge assessment questions, was self administered by participants. Provider's knowledge was classified as good if the score was≥80% and poor if < 60%. Results: Overall, 26.7% (37.3% doctors and 5.9% nurses) had good knowledge of acute oxygen therapy (AOT), 35.9% were aware, and 19.3% used the AOT guidelines. The commonest source of knowledge on oxygen therapy was medical /nursing school (75.2%). The participants' mean knowledge score was 14.75 ± 2.83(possible score of 0-21). Doctors in postgraduate (PG) training obtained the highest score (15.96±2.48) among the participants (F=12.45, df=4, p<0.001). Most doctors (62%) and 23.5% of nurses considered oxygen as a drug. More doctors (52.2%) than nurses (14.7%) believed that a doctor's order was mandatory before oxygen administration, contrary to guidelines recommendations. Most nurses did not know that breathlessness does not always signify hypoxemia and that asymptomatic anemia was not an indication for oxygen. Concerning oxygen prescription, 39.7% of nurses and 64.2% of doctors knew that it should be prescribed to achieve a target saturation range rather than a fixed dose. In acute oxygen delivery in COPD, doctors and nurses exhibited poor knowledge of the appropriate device and flow rate. The reported barriers to oxygen delivery were: a shortage of oxygen supply, inadequate delivery devices, power outages and out of pocket costs. Conclusion: A significant proportion of doctors and nurses had poor knowledge of acute oxygen therapy, poor awareness and infrequently used AOT guidelines, and reported pertinent delivery barriers that warrant educational and administrative interventions.