Experimental studies of quasi-crystalline Al100-xMnx(Si) alloys have shown that the magnitude of electrical resistivity as well as the excess specific heat term Δγ are proportional to the percentage of manganese in the samples as is the case in dilute Al-Mn alloys. The authors argue that the excess specific heat term and the high resistivity (about 150-200 μΩ cm for the quasi-crystalline phase) can be accounted for within the extended Friedel-Anderson s-d model in which the dominant scattering is due to the hybridization of d electrons with the sp conduction band. Therefore, the high resistivity in Al-Mn quasi-crystals is mainly due to the contributions from two effects: the existence of narrow resonant states of manganese at the Fermi level and the existence of correlation lengths of the order of 100-300 which cause the incoherence of transport electrons.