A young Cardiff Blues side slumped to their third straight LV= Cup defeat as holders Gloucester proved too strong.
James Simpson-Daniel scored two second-half tries, with Ryan Mills adding 15 points with his boot.
Andy Hazell's late try emphasised Gloucester's superiority, who had led 21-3 at half-time through Peter Buxton and Tim Molenaar tries.
Ben Blair, playing for the first time in 15 months, scored the Blues' only points with a second-minute penalty.
Gloucester: Voyce; Simpson-Daniel, Molenaar, Fuimaono-Sapolu, Trinder; Mills, Lewis; Murphy, Cortese, Knight, James, Brown, Buxton, Hazell, Deacon.
Replacements: Tindall for Simpson-Daniel (72), Clark for Trinder (52), Runciman for Lewis (57), Thomas for Murphy (67), Dawidiuk for Cortese (56), Chistolini for Knight (67), Evans for James (67), Cox for Deacon (16).
Cardiff Blues: Blair; Mustoe, James, Allen, Czekaj, G. Davies, L. Jones, Yapp, Breeze, Hobbs, Hill, Cook, Navidi, Young, Hamilton.
Replacements: Fish for Blair (62), Patchell for G. Davies (53), Rowlands for L. Jones (57), Trevett for Yapp (57), R. Williams for Breeze (53), Harford for Hobbs (65), Screech for Cook (67), Tucker for Young (74).
Ref: Llyr ap Geraint Roberts (RFU).