Let E be an elliptic curve defined over a number field K. Let m be a positive integer. We denote by E[m] the m-torsion subgroup of E and by K m := K(E[m]) the number field obtained by adding to K the coordinates of the points of E[m]. We describe the fields K 5 , when E is a CM elliptic curve defined over K, with Weiestrass form either y 2 = x 3 + bx or y 2 = x 3 + c. In particular we classify the fields K 5 in terms of generators, degrees and Galois groups. Furthermore we show some applications of those results to the Local-Global Divisibility Problem, to modular curves and to Shimura curves.