The chemistry of Solanum alkaloids up to 1952 was fully reviewed by V. Prelog and O. Jeger in Chapter 21 of Volume III of "The Alkaloids," and more recent work until about 1957 was briefly discussed by the same authors in Chapter 16 of Volume VII. This chapter deals with work reported since that time (with brief mentions of earlier studies if necessary) and includes a tabulated survey of the general occurrence of Solanum alkaloids in the plant kingdom (Table I) and surveys of well-characterized steroid alkaloid glycosides (Table 11) and alkamines (Table 111) isolated from plants listed in Table I. The chemical work on Solanum steroid alkaloids in the last decade was particularly stimulated by the reports of Sato, Mosettig, et al. (1-3) and Kuhn and Low (4), who announced the chemical transformation of spiroaminoketal alkaloids solasodine and tomatidine into 3β-acetoxy-pregna-5,16-dien-20-one and its 5,6-dihydro derivative, respectively—these pregnanes are important intermediates in the industrial production of hormonal steroids, making Solanum alkaloids (especially solasodine) increasingly significant as pharmaceutical starting materials. To clarify this utilization, find suitable alkaloids, and optimize conditions for degrading them to pregnane derivatives, many laboratories extensively studied their chemistry and distribution in the plant kingdom to discover new sources. Solanum alkaloids have been isolated from nearly 250 species of Solanaceae and Liliaceae (generally as glycosides). All 39 well-characterized steroidal alkamines have a C27 cholestane carbon skeleton and belong to five structural groups: (1) spirosolanes (e.g., solasodine); (2) 16-unsubstituted 22,26-epiminocholestanes (e.g., tomatillidine); (3) solanidanes (e.g., solanidine); (4) solanocapsine (unique, with 3β-amino and α-epiminocyclohemiketal moieties); (5) 3-aminospirostanes (e.g., jurubidine, a novel nitrogenous sapogenin from Solanum paniculatum and S. torvum). The most significant progress in the last decade includes the discovery of new alkaloids with novel structures, establishment of their complete stereochemistry, and confirmation via partial/total syntheses—aided by modern methods (ion exchange chromatography, thin-layer/gas liquid chromatography, mass spectroscopy, proton NMR, ORD, circular dichroism, X-ray diffraction) for isolation, identification, and structure elucidation, as well as new quantitative assays for plant materials.