Using a pulsed Townsend technique, we have measured the effective ionization coefficient and the electron drift velocities in CHF(3). The density-normalized electric field intensity E/N ranged from 4 to 250 townsends (Td) (1 Td=10(-17) V cm(2)). The E/N value at which the effective ionization coefficient becomes zero was estimated to be 66 Td. For E/N<20 Td, the electron attachment coefficients are practically constant, and are compatible to within about +/-70% with previously measured values at thermal energies and above.