Isoquinoline alkaloids represent one of the two largest groups of alkaloids, the other being indole alkaloids. The present volume, which is the third of this series, describes the spectral data of about 700 isoquinoline alkaloids and covers the literature up to 1992. The spectral data of the remaining classes of isoquinoline alkaloids will be published in another volume within a year.The compounds are arranged according to their structural types in various subclasses. Within each subclass they are arranged in order of increasing molecular weight. Compounds in the same subclass and having the same molecular weight are arranged in order of increasing carbon number.The UV, IR, 1 H-NMR and 13 C-NMR spectral data are given in descending orders of magnitude. All &egr values in the UV spectra have been converted to log &egr. The chemical shifts in the 1 H-NMR spectral data are presented in ppm and the chemical shifts in the older data published in &tgr values have been converted to &dgr values to ensure uniformity of format. The protons and carbons to which the data refers have been italicised. If any of the data given is that of a salt (e.g. hydrochloride) then this is indicated in brackets before the data. If the compounds are known by more than one name, the older names are given in brackets after the newer one. Spectral data of simple derivatives of compounds are also reported, but only if the data for acetyl, benzoyl, methyl and ethyl derivatives are given. The numbering systems used are given both at the beginning of each sub-class as well as at the end of the book. Compound, molecular formula, molecular weight, plant sources and compound-type indices are also included which should enhance the utility of the book.