We found evidence (Level 2b) for colorimetric capnography to be a valid method for verifying nasogastric tube placement.Capnography also detected nasogastric tube position with very high accuracy. However, since these methods were tested in only a single study with a limited sample size, further research is required before clinical recommendations can be made.Despite the impressive results obtained by using colorimetric capnography, implication for practice is not straightforward. A concern is that the colorimetric capnograph is not produced by the manufacture to fit a NG tube and therefore has to be connected to the NG tube by an adaptor-system. Practical issues therefore have to be resolved if the method is supposed to become a standard procedure in a clinical setting.The execution of the procedure using colorimetric capnography differs between the studies. This systematic review therefore recommends that further research should be done to optimize the execution of the procedure.We also recommend that further research be done to reproduce the results obtained using capnography, since this method was tested only in a single study with a limited sample size.