Gloucestershire reached 31-2 in reply to Leicestershire's 250 on day one at Grace Road.
Leicestershire chose to bat first but were in trouble at 52-5 before lunch with occasional seamer Benny Howell claiming three of the wickets to fall.
Matthew Boyce (55) and Shiv Thakor (75) bailed out Leicestershire with a 125-run stand for the sixth wicket.
Howell removed Boyce to break the partnership and went on to finish with career-best figures of 5-57, the first time he has taken more than two wickets in an innings, while Will Gidman claimed 3-65.
Veteran Claude Henderson thumped 33 off 30 balls to help earn Leicestershire two batting points and Gloucestershire lost Chris Dent and Dan Housego in the final nine overs of the day.
Dent went lbw for six to Robbie Williams (1-12) in the fourth over of Gloucestershire's reply and Housego was caught behind off Ollie Freckingham (1-19).
Nightwatchman David Payne (4no) joined his captain Michael Klinger (9no) through to stumps with Gloucestershire traiing by 219.