The abuse of drugs such as street cocaine is known to cause a variety of toxic effects, some of which involve the lungs and often induce lethal complications. While the toxicity of cocaine itself is reviewed well, the influence of toxic effects of its adulterants on the human body is not thoroughly studied. Therefore, we examined heart blood, femoral vein blood and lung tissue from 11 cases for typically used adulterants in cocaine preparations and check whether if the concentrations in the lung tissue are higher than in the blood. The adulterants were isolated using solid-phase (SPE) and liquid–liquid extraction (LLE) and quantified via high-pressure-liquid-chromatography-time-of-flight–mass spectrometry (LC/TOF–MS). Five adulterants, i.e., phenacetin, lidocaine, diltiazem, levamisole and hydroxyzine, were detected. We found out that the concentration of these substances was often higher in the lung than in the analogous analysed body fluids. It should therefore be considered whether – for the determination in the cause of death – the lung should be examined in addition to heart blood, urine or brain tissue.