This work reports experimental and theoretical first-order rate constants for the reaction of vinyl radical with C4H8 alkenes: 1-butene, 2-butene, and isobutene. The experiments are performed over a temperature range of 300 to 700 K at 100 Torr. Vinyl radicals (H2C=CH) were generated by laser photolysis of vinyl iodide (C2H3I) at 266 run, and time-resolved absorption spectroscopy was used to probe vinyl radicals at 423.2 and 475 nm. Weighted Arrhenius fits to the experimental rate coefficients for 1-butene (k(1)), 2-butene (k(2)), and isobutene (k(3)) yield k(1) = (1.3 +/- 0.3) x 10(-12) cm(3) molecules(-1) s(-1) exp[-(2200 +/- 120) K/T]; k(2) = (1.7 +/- 0.3) x 10(-1)2 cm(3) molecules(-1) s(-1) exp[-(2610 +/- 120) K/T]; and k(3) = (1.0 +/- 0.1) x 10(-12) cm(3) molecules(-1) s(-1) exp[-(2130 +/- 50) K/T], respectively. C6H11 potential energy Surfaces (PESs) for each system were calculated using the G3 method. RRKM/ME simulations were performed for each system to predict pressure-dependent rate coefficients and branching fractions for the major channels. A generic rate rule for vinyl addition to various alkenes is recommended; a similar rate rule for the abstraction of H atoms by vinyl from alkenes is also provided. Some of the vinyl addition reactions exhibit anomalous Evans-Polanyi plots similar to those reported for previous methyl addition reactions.