2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/8433Abundances of R Coronae Borealis stars (RCBs) and Extreme Helium stars (EHes) are discussed. Recent estimates of the $s$-process elements in hot extreme helium stars show enhancements of lighter $s$-process elements (Y, Zr) relative to heavier $s$-process elements, a characteristic shared by RCB stars. It also suggests that atleast some EHe stars went through an episode of $s$-process element synthesis in their earlier evolution. A majority of RCB stars show a high $^{12}$C/$^{13}$C ratio in their atmospheres. A recent analysis of the spectrum of minority RCB star V CrA, however, shows a lower value between 4 $-$ 10. The implications of these results are discussed.14 pages including 6 figures, Invited review presented at "Cosmic abundances as records of stellar evolution and nucleosynthesis", F.N. Bash & T.G Barnes(editors). ASP conf. series, in pressAstrophysicstext