A process for the preparation of a solid catalyst component for the homo or copolymerization of olefins, wherein the solid catalyst component is made from or contains Mg, Ti, halogen and an electron donor selected from cycloalkyl ethers, wherein the process includes the steps of (a) dissolving a Mg based compound and a TiCl3 based compound in a liquid medium further made from or containing a cycloalkyl ether and a compound of formula R2OH where R2 is a C1-C20 hydrocarbon group, in which the Ti/Mg molar ratio ranges from 0.1 to 0.5, the cycloalkyl ether/Mg ratio ranges from 1 to 4 and the ROH/Mg molar ratio ranges from 1 to 4; and (b) adding, to the solution coming from step (a), SiCl4 in an amount such that the R2OH/SiCl4 molar ratio ranges from 0.5 to 1.5 and maintaining the temperature in the range 50-150° C. thereby precipitating the solid catalyst component particles.