We report on studies of the effect of annealing on magnetic properties and giant magneto-impedance (GMI) effect in Co69Fe4Cr4Si12B11 amorphous microwires with diameters of 90 and 55 μm produced by the Tailor-Ulitovski method allowing rapid quenching of composite glass coated microwires followed by glass removal techniques and warm drawing. Drawn samples have been annealed at temperatures between 250°C and 450°C. We studied GMI effect and hysteretic magnetic properties in produced microwires. Annealing considerable affects hysteresis loops and GMI effect of studied microwires. Optimization of GMI effect has been observed for samples annealed at 400°C.