© 2016 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb-1 collected by LHCb at s=7 and 8 TeV, is used to reconstruct 63±9 Ωb-→Ωc0π-, Ωc0→pK-K-π+ decays. Using the Ξb-→Ξc0π-, Ξc0→pK-K-π+ decay mode for calibration, the lifetime ratio and the absolute lifetime of the Ωb- baryon are measured to be τΩb-/τΞb-=1.11±0.16±0.03, τΩb-=1.78±0.26±0.05±0.06 ps, where the uncertainties are statistical, systematic and from the calibration mode (for τΩb- only). A measurement is also made of the mass difference, mΩb - mΞb-, and the corresponding Ωb- mass, which yields mΩb - mΞb-=247.4±3.2±0.5 MeV/c2, mΩb-=6045.1±3.2±0.5±0.6 MeV/c2. These results are consistent with previous measurements.