AIFe(2)B(2) and AlFe2-xCoxB2 (x = 0-0.30) were synthesized from the elements in three different ways. The samples were characterized by powder X-ray,diffraction, Rietveld refinements energy-dispersive X-ray spectroscopy, and magnetic measurements. Using Al flux the formation of AIFe(2)B(2) single crystals is preferred. Arc melting enables the substitution of similar to 6% Co. This substitution of Fe by Co decreases the Curie temperatute T-C from 290 to 240 K. The highest. Co substitution up to 15% is-achieved by spark plasma sintering,(SPS). T-C is reduced to 205 K. In all cases an excess of Al is necessary. to void the formation of ferromagnetic FeB. Al13Fe4-xCox is the common by product. T-C and the cobalt content are linearly correlated. The transition paramagnetic-ferromagnetic :remains sharp, for all examples. The magnetic entropy change of the Co-containing samples-is., comparable to AIFe(2)B(2). SPS synthesis yields, in short reaction times,. a homogeneous and dense material with small amounts of paramagnetic Al13Fe4-xCox as an impurity,,which can serve as sinter additive. These properties make AlFe2-xCoxB2. a promising magnetocaloric material for applications between room temperature and 200 K.