Microwave rotational spectra were measured for eight isotopomers of eta(5)-C5H5Cr(CO)(2)NO using a pulsed-beam, Fourier transform spectrometer. The normal isotopomer is a near-symmetric rotor with A = 1001.693(2), B = 797.2724(6), and C = 797.0143(6) MHz. This complex has a "piano-stool" type structure, with one symmetry plane. The accidental, near-symmetric top inertia tenser gives a dear indication of different bonding and structural parameters for the nitrosyl group and the carbonyl groups, since 3-fold symmetry for the nitrosyl and carbonyl groups would result in a much larger value for B - C. The nitrosyl and carbonyl groups form different angles with the z-axis which passes through the Cr atom and center of C5H5. The C5H5-Cr-NO angle is 128 degrees, and the C5H5-Cr-CO angle is 120 degrees. The distance from the Cr atom to the C5H5 ring is z (Cr-C5H5) = 1.86 Angstrom. The a-axis forms an angle of 4 degrees with the z-axis. Other structural parameters are obtained and discussed. The C5H5 ring is oriented so that two of the cyclopentadienyl carbon atoms are staggered with respect to the NO nitrogen atom. The N-14 quadrupole coupling values are eQq(aa) = 0.312(2) and eQq(bb) = -0.448(2) MHz.