Develop and validate a toxicological screening by High Resolution mass spectrometry (HR/MS) on whole blood taken from MITRA®, a volumetric micro-sampling system (VAMS). In both clinical and forensic toxicology, screening remains an essential element in the management of the patient and the search for the cause of death. Performed on urine and/or plasma, it uses chromatographic methods coupled with different detection systems such as HR/MS. The reduction in sample volumes and the grouping of analyses in specialized laboratories explain the search for new analytical approaches to develop toxicological screening on alternative matrices such as VAMS. Six whole blood solutions were overloaded with 85 licit and illicit drugs to optimize the pre-analytical phase and to determine the detection limits (LD) of drugs. Twenty microliters of each solution are sampled to MITRA® (Neoteryx). After drying 24 hours at room temperature, MITRA® elution is carried out in 500 μL of a solvent mixture by stirring and sonication. After evaporation, the dry extracts were taken up by 50 μL of solvents and 10 μL injected into the chromatographic system (Vanquish® LC) coupled to a QExactive Focus® mass spectrometer equipped with an electrospray ionization. The identification of the compounds is carried out from the TraceFinder® 4.0 software (ThermoFisher Scientific) compared to our library including 1500 referenced compounds. To study the feasibility in clinic, we sampled at the same time, 20 μL of plasma, whole blood and MITRA® fingertip blood to perform screenings in ten patients hospitalized in Toxicological Critical Care for acute poisonings. Our extraction protocol coupled with HR screening has among detect/identify 76 compounds out of the 85 present in overloaded solutions. Cannabis derivatives are not detected and barbiturates are poorly (LD = 250 ng/mL). For other compounds, detection limits are less than 25 ng/ml for opiates, 12.5 ng/mL for amphetamines and benzodiazepines, 2.5 ng/mL for tramadol, mephedrone and benzoylecgonine, 1.25 ng/mL for norfentanyl. In ten poisonned patients, screenings performed on plasma, whole blood and MITRA®, show similar résults. Analogy of detection corresponding to 100% for whole blood compared to plasma, and 98% for MITRA® compared to whole blood. In MITRA®, ethylglucuronide was detected but not identified in two patients. MITRA® extraction yields/whole blood ranged from 80.6 to 108.7% for licit and illicit drugs and their metabolites. Our study reports an excellent concordance (R2 = 0.9997) between the areas of the molecules obtained on 20 μL MITRA® and those obtained from 20 μL whole blood sample. We report for the first time an original method of toxicological screening on VAMS. Our pre-analytical phase is still long but allows us to extract 90% of the molecules present in the overloaded solutions. In MITRA®, the detection/identification of molecules is similar to that on whole blood with very good extraction yields and satisfactory detection limits for the majority of the compounds tested. The lack of sensitivity for some compounds, as cannabis derivatives and barbiturates, is not related to the sampling on MITRA® but to the poor detection of acidic compounds in our HR/MS method. The excellent concordance in patients between whole blood and MITRA® samples shows a comparable distribution of substances between capillary and peripheral streams. This study confirms the major interest of VAMS in toxicology fields, opening up new perceptives, in paediatrics or in addictology by fingertip sampling, in forensics with the possibility of working on very small volumes, such as bloodstains, to carry out mass screening during events, to monitor environmental epidemiology and occupational health studies or to exchange samples due to MITRA® samples stability and their easy transport by post.