Planetary was previewed in issue #33 of Gen¹³ and issue #6 of C-23, both dated September 1998. The first issue of the series was cover-dated April 1999. Originally intended to be a 24-issue bi-monthly series, the series was on hold from 2001 to 2003 due to illness of writer Warren Ellis and other commitments by Cassaday. Laura Martin (also credited as Laura DePuy) colored almost every issue of the series. The series recommenced in 2004 and concluded with issue #27 in October 2009.