data are very useful for such purposes in actual forensic toxicological practice. Extensive data are presented for simultaneous analysis of six phenethylamine-type designer drugs. The drugs are 2,5-dimethoxyphenethylamine (2C-H), 2,5-dimethoxyamphetamine (2,5-DMA), 4-bromo-2,5-dimethoxyphenethylamine (2C-B), 4-bromo-2,5-dimethoxyamphetamine (DOB), 4-iodo-2,5-dimethoxyphenethylamine (2C-I), and 4-iodo-2,5-dimethoxyamphetamine (DOI). The data include their proton nuclear magnetic resonance (NMR) spectra, infrared spectra, retention times detected by liquid chromatography (LC) and gas chromatography (GC), thin-layer chromatography (TLC) data using seven solvent mixture systems, electrospray ionization (ESI) mass spectra without derivatization, and electron ionization (EI) mass spectra with trifluoroacetyl (TFA) derivatization. Quantitative reliability was also tested for these compounds by LC-mass spectrometry (MS) and GC-MS in high concentration ranges. The data concerned is intended to serve for screening, identification, and quantitation of the drugs contained in seized tablets, crystals, and powder; the