This volume describes mononuclear organotin compounds with bonds between the tin atom and Group 15 elements (N, P, As, Sb, Bi). It continues the coverage of the organotin-nitrogen compounds, started with volume 18 in 1990 which spans a large variety of substances including compounds with additional bonds to hydrogen, Group 16, or Group 17 elements. Another important chapter is devoted to the organotin-phosphorus compounds. The first authentic organotin phosphine was synthesized in 1959. Numerous other Sn-P compounds have subsequently been prepared and characterized. Many of them are interesting with respect to their use as synthons for novel organophosphorus compounds. Decreasing stability in the series Sn-AS, Sn-Sb, and Sn-Bi restrics the number of possible organotin derivatives. To date, no nomonuclear organotin-bismuth compounds have been isolated, but some evidence has been presented for the intermediate existence of one such compound.