Carbon Stars and Nucleosynthesis in Galaxies

The role of carbon stars in the build-up of chemical elements in galaxies is discussed on the basis of stellar evolution calculations and estimated stellar yields, abundance analyses of AGB stars, galactic-evolution models and abundance trends among solar-type disk stars. We conclude that the AGB stars in general, and carbon stars in particular, probably are main contributors of $s$-elements, that their contributions of flourine and carbon are quite significant, and that possibly their contributions of lithium, $^{13}$C and $^{22}$Ne are of some importance. Also contributions of N, Na and Al are discussed. The major uncertainties that characterize almost any statement concerning these issues are underlined