Ultraviolet absorption cross sections of methylchloroform CH3 CCl3 have been measured in the wavelength interval 180--240 nm and temperature range 210--295 K. Numerical values are given and compared with existing data at ambient temperature. Photodissociation coefficients have been calculated for altitudes between 20 and 45 km and appear to be significantly lower than generally considered. The substantial decrease in absorption cross sections observed at low temperatures and &lgr; > 210 nm has only a minor influence on overall photodissociation coefficients. Relative contributions of photodissociation and reaction with OH radicals as potential sinks for methylchloroform at stratospheric altitudes are briefly discussed.