Solvent effects and sample concentration effects on the structural changes of propylamide have been investigated by FT-IR measurement using principal component analysis. The absorption peaks observed at higher frequency and higher intensity when using chloroform and dichloromethane compared to benzene. The concentration study reveals that propylamide form a high degree of association in benzene. Shifting the composition of the solvent from benzene to chloroform or dichloromethane, the intensity that comes from the association of molecule decreases since association is more favored in non-polar solvents. In spectra of propylamide in mixtures of benzene and dichloromethane an increment in the intensity of bands as well as a solvatochromic effect (blue shift) is observed upon increasing the polarity of the medium (solvatochromic effect).