A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at√s = 8TeV from pp collisions corresponding to an integrated luminosity of 20.3 fb-1 are examined. Particles producing anomalously high ionisation, consistent with long-livedmassive particleswith electric charges from |q| = 2e to |q| = 6e are searched for. No signal candidate events are observed, and 95% confidence level crosssection upper limits are interpreted as lower mass limits for a Drell-Yan productionmodel. The mass limits range between 660 and 785 GeV.