Chitosan derivatives (ChD) and microfibrillated cellulose (MFC) show wide differences in water barrier properties when applied as single-component coating. Alkyl chitosan (Ach) increases the hydrophobicity while MFC, carboxymethyl chitosan (CCH) and quaternary chitosan (QCh) coatings increase the hydrophilicity of paper surface, these effects being clearly evidenced by the values of contact angle and Cobb index; the WVTR drops by 30% for the CCh and ACh coatings, due to the presence of hydrophobic groups in the case of the ACh and due to a compact and uniform film structure in that of the CCh (proved by SEM images). However, the combinations of MFC with ChDs in composite coatings led to poorer water barrier properties than individual ChD films; one can suppose the effect is caused by uneven covering and lower ChD content in the coating layer (1 g/m² instead of 2 g/m²).