The aim of this in vitro study was to evaluate the surface properties of four composite materials with different organic contents and Streptococcus mutans (S. mutans) adhesion to the surfaces after 4 h. TCD-based (CT; Charisma Topaz), Bis-GMA-based (ESQ; Estelite Sigma Quick), UDMA-based (GA;G-aenial Anterior), ormocer-based composites (AF;Admira Fusion) were selected. Polystyrene was used as a control group. Fifteen cylindrical specimens (10 mm diameter x 2 mm depth) were prepared for each group. Surface roughness (SR) was investigated with AFM. Hydrophobicity and surface free energy (SFE) was determined by the sessile drop method. Early adhesion of S. mutans on the materials were evaluated by optical density readouts on a spectrophotometer. Surface morphology and S. mutans bacterial adhesion (SMBA) were examined using SEM. Data were analyzed by ANOVA, post-hoc Dunnett (p < 0.001), and Tukey tests (p < 0.05).Spearman's rho coefficient was used to investigate the correlation between SR and SMBA. There was a statistically significant difference between the test groups in terms of SR (p < 0.05).AF showed the highest roughness value while ESQ showed the lowest. No statistically significant difference was observed between the test groups in terms of total SFE and hydrophobicity (p > 0.05) while a statistically significant difference was obtained between the test groups in terms of surface SMBA (p < 0.05).The highest SMBA was observed in GA while ESQ showed the lowest. There was a significant correlation between SMBA and SR in the AF (r = 0.929; p = 0.001), CT (r = 0.976; p = 0.001) and ESQ(r = 0.731; p = 0.040).There is a correlation between the SR of composite materials with different organic contents and SMBA. It can be stated that the Bis-GMA based composite material has clinically acceptable physical properties due to its low SR and S. mutans adhesion.