As a current case of needlestick injury (NSI) has demonstrated, it is obvious that in clinical practice there is often uncertainty about the procedure if the index patient refuses a blood test or is not able to give his/her consent. The question about the legality of implementing HBV, HCV and HIV testing after NSI is commented on from different points of view: occupational medicine, infection control, virology and the legal system. The testing of the index patient - without his/her consent - seems to be appropriate. The protection of health care workers should be given priority over the right of the index patient "not wanting to know" about his/her infection status.