Abstract. We analyze the time-frequency concentration of the Gabor orthonormal basis G(f, 1, 1) constructed by Høholdt, Jensen, and Justesen. We prove that their window function f has near optimal time and frequency localization with respect to a non-symmetric version of the Balian-Low Theorem. In particular, we show that if (p, q) = (3/2, 3), then R |t| p− |f (t)| 2 dt < ∞ and R |γ| q− | b f (γ)| 2 dγ < ∞, for 0 < ≤ 3/2, but that both integrals are infinite if = 0.