The rate constants of the reactions of NO3 with cyclopentene, cyclohexene, cycloheptene, 1-methylcyclohexene, and methylenecyclohexane have been measured as a function of temperature at low pressure in a fast flow system with LIF detection of NO3. The measured room temperature (298 K) rate constants for these reactions are (cm(3) molecule(-1) s(-1)) (0.70 +/- 0.20) x 10(-12), (0.64 +/- 0.08) x 10(-12), (0.57 +/-0.10) x 10(-12), (9.7 +/- 1.6) x 10(-12), and (0.66 +/- 0.09) x 10(-12), respectively. The proposed Arrhenius expressions for the studied reactions are (in units of cm(3) molecule(-1) s(-1)) k(1) = (52 +/- 49) x 10(-12) exp[-(1329 +/- 330)/T], k(2) = (7.3 +/- 1.9) x 10(-12) exp[-(707 +/- 188)/T], k(3) = (1.9 +/-0.02) x 10(-12) exp[-(368 +/- 16)/T], k(4) = (1.0 +/- 0.3) x 10(-12) exp[(675 +/- 96)/T], and k(5) = (18.2 +/- 8.3) x 10(-12) exp[-(1000 +/- 182)/T], respectively. The influence of substitution in the double bond and the ring size effect in unsubstituted cyclic monoalkenes has been investigated for the reactivity of the NO3 radical reactions. The rate coefficients and the activation energies for the reaction of the nitrate radical with methylenecyclohexane and 1-methylcyclohexene have also been compared with the corresponding values of some selected terpenes with similar structure to these compounds.