We report on magnetic and magnetotransport properties of single-crystalline Co₂MnSi films grown by using conventional pulsed laser deposition (PLD) method on moderately heated semiconductor GaAs(001) substrates. The films exhibit the expected high Curie temperature and a strong in-plane uniaxial magnetic anisotropy with the easy axis of magnetization along the [1-10] direction. A saturation magnetization of 950 emu/cm³ was measured at 5 K. The temperature dependence of the resistivity shows metallic behavior down to low temperatures. At 5 K, a rather large negative magnetoresistance (MR) of 1.26% has also been observed.