A complete scenario on nodal radial solutions to the Brezis Nirenberg problem in low dimensions *

where with 3 ⩽ N ⩽ 6 and B is the unit ball of IRN. We compute the asymptotics of the solution u as well as ||u||∞, its first zero and other relevant quantities as λ goes to a critical value . Also the sign of is established in all cases. This completes an analogous analysis for N ⩾ 7 given in [12].