Exponentially correlated Gaussian wave functions of 1200 terms were employed to compute expectation values of the quadrupole moment, Theta, for the ground state of helium dimer. The quadrupole moment was calculated in the frames of the Born-Oppenheimer approximation for a wide range of internuclear distances, 0.0 less than or equal to R/a(0)less than or equal to 15.0. At the equilibrium distance Theta=-6.2(1)x10(-4) ea(0)(2) and the estimated vibrational average amounts to -5x10(-7) ea(0)(2). For small R, the quadrupole shielding function, gamma(R)=-Theta(e)(R)/Theta(n)(R), was constructed, which allowed the quadrupole shielding factor gamma(infinity) of beryllium atom to be estimated as equal to +1.5(1). As the wave functions employed are the most accurate variational wave functions for He-2, the quadrupole moment results presented in this paper may serve as benchmarks. (C) 2000 American Institute of Physics. [S0021-9606(00)30716-4].