We present ^ { 12 } CO J=1-0 observations from the Caltech Millimeter Array of a field in the nearby spiral galaxy M81 .
We detect emission from three features that are the size of large giant molecular clouds ( GMCs ) in the Milky Way Galaxy and M31 , but are larger than any known in M33 or the SMC .
The M81 clouds have diameters \sim 100 pc and molecular masses \sim 3 \times 10 ^ { 5 } M _ { \odot } .
These are the first GMCs to be detected in such an early type galaxy ( Sab ) or in a normal galaxy outside the Local Group .
The clouds we have detected do not obey the size–linewidth relation obeyed by GMCs in our Galaxy and in M33 , and some of them may be GMC complexes that contain several small GMCs .
One of these does show signs of sub-structure , and is shaped like a ring section with three separate peaks .
At the center of this ring section lies a giant HII region , which may be associated with the molecular clouds .