Abstract The quadrupole interaction frequencies ω 0 = 3eQ 1V zz 41(21-1) h ̵ in the 5 − state of 118Sn have been measured by time differential perturbed angular correlation technique in Sn, Sb and (95% Sn+5% Sb) environments. The ω 0 for 116Sn was determined in Sn environment only. With the help of the known electric field gradient 1) of Sn in a Sn lattice the quadrupole moments have been deduced as Q(5 −, 118 Sn) = ±0.10(4) b and Q(5 −, 116 Sn) = ±0.165(60) b . These values together with the known 2) quadrupole moment of the analogous 5 − state in 120Sn are interpreted in terms of the pure single-particle model. The data exhibit the expected strong systematic variation of Q I with the number of particles in the h 11 2 . subshell which is being filled with 1, 3 and 5 neutrons in 116Sn, 118Sn, and 120Sn, respectively.