We present a new evaluation of thermonuclear reaction rates for astrophysics involving proton and alpha-particle induced reactions, in the target mass range between A=14 and 40, including many radioactive targets. A method based on Monte Carlo techniques is used to evaluate thermonuclear reaction rates and their uncertainties. At variance with previous evaluations, the low, median and high rates are statistically defined and a lognormal approximation to the rate distribution is given. This provides improved input for astrophysical model calculations using also the Monte Carlo method to estimate uncertainties on isotopic abundances.