The theoretical study of low-temperature lattice thermal expansion of the II-VI semiconductor ZnS is attempted. The generalized Gruneisen gammas of the elastic waves propagating in different directions with respect to the [001] crystallographic axis of ZnS are calculated using the second- and third-order elastic constants. The values of mode Gruneisen gammas gamma(j) are determined and found generally positive except from gamma(2) at theta = 25 degrees to theta = 65 degrees. The low-temperature limit of the Gruneisen gamma gamma(j) are determined and found generally positive except from gamma(2) at theta = 65 degrees. The low-temperature limit of the Gruneisen gamma gamma is determined and compared with experimental values. Using this gamma, we calculated the Brugger gamma gamma(Br) and hence the low-temperature volume lattice thermal expansion gamma(L). It is expected that the volume expansion is positive down to absolute zero for ZnS.