This article is from the rec.arts.sf.written FAQ, by Evelyn C. Leeper email@example.com with numerous contributions by others.
Opinion seems to be divided to reading them in order of the internal
chronology (to avoid spoilers) or in order of publication. In either
case, MIRROR DANCE, MEMORY, and KOMARR should be read last or the
reader will likely miss some important connections. And I recommend
reading SHARDS OF HONOR first in either case. The more recent editions
of the Baen paperbacks have an internal chronology in the back of each
By order of publication, the books in the series are SHARDS OF HONOR
(1986), THE WARRIOR'S APPRENTICE (1986), ETHAN OF ATHOS (1986), FALLING
FREE (1988), BORDERS OF INFINITY (1989), BROTHERS IN ARMS (1989), THE
VOR GAME (1990), BARRAYAR (1991), MIRROR DANCE (1994), CETAGANDA
(1996), MEMORY (1996), KOMARR (1998), and A CIVIL CAMPAIGN (1999).
FALLING FREE and ETHAN OF ATHOS are basically independent of the other
storylines. Bujold's other book, THE SPIRIT RING, is a fantasy not set
in the same universe.
By internal chronology (my recommendation), the order is FALLING FREE
(peripheral), SHARDS OF HONOR, BARRAYAR, THE WARRIOR'S APPRENTICE, the
short story "The Mountains of Mourning" in BORDERS OF INFINITY, THE VOR
GAME, CETAGANDA, ETHAN OF ATHOS (peripheral), the short story "Labyrinth"
in BORDERS Of INFINITY, the short story "Borders of Infinity" in BORDERS
OF INFINITY, BROTHERS IN ARMS, MIRROR DANCE, MEMORY, KOMARR, and A CIVIL
[People have sent many variations to this, based on which books they think
are stronger or weaker. I will not include all the arguments here.]
[Provided by Peter L. Edman [firstname.lastname@example.org],
email@example.com [Robert A. Woodward], and others.]