The invention relates to the field of nuclear engineering and can be used in the manufacture of fuel rods and fuel assemblies for heavy liquid metal cooled reactors, and also in the manufacture of fuel rod simulators for use in irradiation devices designed to test the operability of real fuel assemblies. The present cladding of a fuel rod for a heavy liquid metal cooled reactor is in the form of a weldless tubular element with helically-coiled fins disposed on the outer surface of said element, which is made from a ferritic-martensitic chromium-silicon steel with a minimum ferrite grain size of 7 on the GOST 5639 scale, wherein each fin has an opening angle of from 22 to 40 DEG C (preferably from 30 to 40 DEG C) and the cross-section of the fin is in the shape of a trapezoid with rounded corners at the top of the trapezoid and smooth corners at the base of the trapezoid. Also disclosed are a fuel rod comprising the above cladding, and a fuel assembly. The technical result of the invention is an improvement in the performance characteristics of fuel rods and assemblies as a result of the long-term resistance of the cladding in the environment of a heavy liquid metal coolant such as lead or a eutectic of lead and bismuth.