  Barium stars and technetium-poor, extrinsic S stars are binary systems with a
white dwarf companion, and with orbital elements similar to those of symbiotic
systems. One may thus wonder whether these various families of binary systems
involving red giant stars are somehow related. This question is actually
twofold: (i) Do barium and binary S stars exhibit some symbiotic activity? (ii)
Do symbiotic systems exhibit overabundances of s-process elements like barium
and S stars? This paper reviews the current situation regarding these two
questions.
