Dark matter ( DM ) particle annihilation or decay can produce monochromatic \gamma -rays readily distinguishable from astrophysical sources . \gamma -ray line limits from 30 GeV to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a \gamma -ray line analysis , and integrated over most of the sky .
We obtain \gamma -ray line flux upper limits in the range 0.6 - 4.5 \times 10 ^ { -9 } \mathrm { cm } ^ { -2 } \mathrm { s } ^ { -1 } , and give corresponding DM annihilation cross-section and decay lifetime limits .
Theoretical implications are briefly discussed .