The ultraviolet absorption spectra of CH₂Br and CH₂BrO₂ radicals and the kinetics of their self-reactions have been studied in the gas phase at 298 K by using the pulse radiolysis technique. Absorption cross sections were quantified over the wavelength range 220-350 nm. Measured cross sections near the absorption maxima were σ_CH2Br(280 nm) = (6.26 ± 1.15) × 10^-18 cm² molecule^-1 and σ_CH2BrO2(250 nm) = (7.20 ± 0.83) × 10^-18 cm² molecule^-1. Errors represent statistical errors (2σ) together with our estimate of potential systematic errors (10%). The absorption cross-sectional data were then used to derive the observed self-reaction rate constants for reactions 1 and 2, defined as -d[R]/dt = 2k_oba[R]² (R = CH₂Br or CH₂BrO₂) of CH₂Br + CH₂Br → products (1) CH₂BrO₂ + CH₂BrO₂ → products (2) k₁ = (2.93 ± 0.60) × 10^-11 cm³ molecule^-1 s^-1 and k_2obs = (3.26 ± 0.31) × 10^-11 cm³ molecule^-1 s^-1 (quoted errors represent 2σ). These results are discussed with respect to previous studies of the absorption spectra and kinetics of peroxy radicals.