Two laser magnetic resonance patterns for 14NO2 and six patterns for 15NO2, observed using six CO laser transitions, have been analyzed to yield spin corrected zero-field vibration–rotation transition wave numbers and zero-field spin–rotation splittings. The 14NO2 results are in good agreement with results obtained from conventional infrared grating studies. The 15NO2 results allow new values of ν0 = 1582.107 ± 0.008, A′ − A″ = −0.2116 ± 0.0011, and DK′ − DK″ = −1.39 ± 0.20 × 10−4 cm−1 to be determined for the ν3 fundamental of that molecule (errors are 3 standard deviations). Two spectral figures and a list of assigned Zeeman lines are presented to permit using this stable molecule as an aid in adjusting newly constructed instruments. Closed form approximate intensity expressions are given for Zeeman transitions of the type observed in this work, i.e., for sharp partially spin forbidden Zeeman transitions in A type bands of near prolate asymmetric rotors.