A process for the manufacture of ethylene polymers by homopolymerization and copolymerization of ethylene at pressures of from 500 to 5,000 bars and at from 50.degree. to 450.degree. C, with subsequent isolation of the polymers in high pressure product isolation zones and low pressure product isolation zones. The various parallel product isolation zones are at different temperatures, and the mean product residence times in the zones may be identical or different. Very different products, in amounts which can be chosen according to requirements, and with mutually independent polymer properties, can be obtained using only one high pressure polymerization system.