Two overpressured layer chromatography (OPLC) systems were developed for the screening of toxicologically relevant basic drugs in forensic and clinical contexts. The OPLC1 system was trichloroethylene - methylethylketone -n-butanol - acetic acid - water 17+8+25+6+4 and the OPLC2 system was butyl acetate - ethanol - tripropylamine - water 85+9.25+5+0.75 with presaturation. Both systems were tested on high performance silica gel plates. The Rfvalues of the drugs were reproducible, the peak shapes were symmetrical, and the chromatographic systems showed low mutual correlation (r = 0.103). The separation numbers (SN) were 27.5 and 29.2 for OPLC1 and OPLC2, respectively, which are more than two times higher than those obtained with TLC systems in general. The combination of the systems was demonstrated to be feasible in the screening for drugs in autopsy urine samples, utilizing automated identification by hRfc/UV library search with combined dual-system reporting.