We present the study of heat capacity C(T) of single-crystalline NdB6 prepared by zone floating which orders in an A-type collinear antiferromagnetic structure below T-N approximate to 8 K. In zero field, we have observed a magnetic transition at T-N = 7.45 K in a magnetic field of 3 T, this transition is shifted to 7.6 K. From the observed results, we determined the magnetic entropy and the magnetic part of C(T) by subtracting the phonon and electronic part of the heat capacity of isostructural LaB6. (c) 2006 Elsevier B.V. All rights reserved.