[en] In this study, the effect of addition of single-walled carbon nanotubes (SWCNTs) on the morphological properties of poly(3,4-ethylenedioxythiophene/poly(4-styrenesulfonate) (PEDOT:PSS) has been investigated using scanning electron microscope (SEM) as well as the surface roughness evaluation by atomic force microscopy (AFM). The spin-coated films of PEDOT:PSS and PEDOT:PSS with addition of SWNTs (0.5 % by wt.) on glass were compared in our study. Experimental results show that surface roughness of PEDOT:PSS layers increases after addition SWNTs to the solution - from 3.50 nm for the samples without SWNTs to 4.65 nm for the samples with SWNTs. The analysis of SEM images showed that there are some agglomerations of SWNTs on the surface of PEDOT:PSS/SWCNT composite film