Background and Purpose: Inserting a nasogastric tube, though a common clinical procedure with widespread use for critically ill patients, can produce unexpected complications so that tube misplacement into the lungs is a potential complication with serious consequences. The reliability of common bedside methods to differentiate between pulmonary and gastric placement has not been acceptable. The goal of this study was to review the diagnostic accuracy of methods in detecting inadvertent airway intubation and verifying correct placement of nasogastric tube and restrictions. Methods: A review of Pub Med, Medline and CINAHL databases has been conducted to identify peer-reviewed, English language, human subject research studies published between the years 1994 and 2013.The research was conducted on the confirmation, methods and restrictions of NGT in the adult's population. Out off 151 English publications, 29 were duplicates and 2 were animal studies. Quality assessments, data extractions and analysis were completed on all included studies. Results: Although methods for assessing correct NGT location at the bedside are available, each has its limitations. The methods include auscultation (the most common method), PH testing of aspirates, capnography, insertion under direct vision and magnetic detection. All studies used X-rays as the reference standard for comparison since auscultation is unreliable. Conclusion: While none of the existing bedside methods for testing the position of nasogastric tubes is totally reliable, the evidence suggest that using more than one method for confirmation of nasogastric tube position is necessary.