The results of analyzing asymmetry in the H₂O maser lines at λ = 1.35 cm are presented. We investigated in detail the known mechanism of the asymmetry origin due to the hyperfine structure of the 6₁₆ → 5₂₃ transition and different (not equidistant) positions of the corresponding triplet components. The triplet of the lines is characterized by the sum of extinction factors that are continuously transformed into a single-peaked asymmetric extinction coefficient, with the increase in the Doppler widths (characterizing by effective Doppler velocity ud). A noticeable asymmetry corresponds to ud ≤ 0.5−1 km s¯¹. For higher values of ud the extinction factor approaches a Gaussian shape with the decreasing magnitude of the profile asymmetry. An appreciable asymmetry in unsaturated maser lines can only arise at ud ≤ 0.5 km s¯¹, if there are very narrow linewidths (Δu ≈ 0.2−0.4 km s¯¹). But observed saturated masers possess a fairly high degree of the line asymmetry, 10−40%. Most probably, this asymmetry is a result of rebroadening of the linewidth up to the value that is comparable to the width of the asymmetric extinction coefficient.