In present study we performed gas-liquid chromatographic analysis of exhaled breath condensate to measure volatile fatty acids (C2 — acetic, C3 — propionic, C4 — butanoic, isoC4 — isobutyric, C5 — valerianic, C6 — caproic, C7 — heptanoic) and fatty acid with a long aliphatic chain (C14:0 — myristic, C15:0 — pentadecanoic, C16:0 — palmitic, C16:1 — palmitooleic, C17:0 — heptadecanoic, C17:1 — heptadecenoic, C18:0 — stearic, C18:1 — oleic, C18:2 — linolenic, C18:3ω3 — α-linolenic, C20:4ω6 — arachidonic) in patients suffering from moderate chronic obstructive pulmonary disease (2nd stage, GOLD). We revealed the increase of the total amount of short chain fatty acids (C2, C3, C4, C5) and polyunsaturated (C18:2, C20:4ω6) fatty acids, meanwhile the level of saturated fatty acids (C16:0, C17:0, C18:0) decreased.