Tested respiratory viruses: influenza A virus, respiratory syncytial virus (RSV) and human metapneumovirus (hMPV), were successfully identified directly from crude cell cultures using liquid chromatography-tandem MS (LC-MS/MS). The identification was preceded with the simple, generic and fast sample preparation method. The determined identification limit was only one order of magnitude higher than required for identification from a clinical specimen. Because identification is based on amino acid sequences deposited in GenBank, other viruses are likely to be identified using the developed method. Further improvement of the sample preparation method, may soon bridge the gap between research and clinical diagnostics. We conclude that MS-based techniques have the potential to become a complementary method to PCR in viral diagnostics.