The review refers to the selected literature published since 1998 that concerns analysis of morphine and related compounds by liquid chromatography or capillary electrophoresis with mass spectrometry. The cited papers describe application of HPLC/MS and CE/MS in analysis of opiates but also discuss usefulness of various atmospheric pressure ionization sources (electrospray, atmospheric pressure chemical ionization and sonic spray) as well as the influence of experimental parameters on ionization efficiency of these sources. The reproducibility of mass spectra obtained using collision-induced dissociation is also an important topic. The reproducibility is essential for HPLC-MS to become an alternative to routine and widespread GC-MS. In comparison with HPLC-MS, CE-MS is less robust and so far has been less frequently used.