Highly substituted cellulose ethers containing the carbazole moiety as a side chain substituent were prepared from cellulose acetate, alkyl bromides and N-(bromoalkyl)carbazoles in NaOH/DMSO. Two specific samples are discussed. The first is designated as (dodecyl)2.3(N-4-carbazolylbutyl)0.7, cellulose, where the subscripts correspond to the average number of substituents per anhydroglucose ring as determined from H-1 NMR spectra. The second, (dodecyl)3.0 cellulose, contains no carbazole groups. Stable monolayers of these polymers can be spread at the air-water interface from dilute chloroform solution. The pressure-area isotherms recorded for the two samples are nearly identical, both exhibiting an expanded liquid phase at surface areas between 120 and 100 angstrom per anhydroglucose unit. The similarity of the two isotherms clearly indicates that the presence of the relatively large carbazole group does not result in an increase in the molecular area at which the liquid analogous phase occurs. This important observation suggests that the chromophore is oriented with the aromatic ring system perpendicular to the water surface. Monolayers can be efficiently transferred to both hydrophobic glass and aluminum coated substrates by the vertical dipping technique.