Objective: Colorectal cancer is one of the most deadly cancers in the world. Docetaxel (DTX) is a potentially important chemotherapeutic agent for the treatment of cancer. Many studies have attempted to improve its bioavailability and efficiency using different nanoparticulate drug delivery systems. Significance: In current study, PEGylated solid lipid nanoparticles (SLNs) containing DTX were prepared and modified with AS1411 anti-nucleolin aptamers to target nucleoin receptors on colorectal cancer cells. Methods: Nanoparticles were characterized and the morphology was evaluated. In vitro studies were investigated on murine colon carcinoma (C26) and Chinese hamster ovary (CHO) cell lines. Then in vivo antitumor efficacy and survival analysis were evaluated in mice bearing C26 tumor model. Results: Results showed 135-140 nm particle size and about 78% DTX entrapment efficiency for active targeted samples. PEGylated and aptamer-targeted SLNs containing DTX had the lowest IC50 (0.28 and 0.11 nM for 3 and 6 hours incubation respectively) and higher cellular uptake values in C26 cell line. Also in vivo results demonstrated that PEGylated and aptamer-targeted SLNs containing Docetaxel (Apt-PEG-SLN-DTX) improved antitumor activity and inhibited tumor growth in C26 tumor bearing mice. Conclusion: These results suggested that PEGylated and aptamer-targeted SLNs containing DTX exhibited efficient characteristics in tumor inhibitory against murine C26 carcinoma model.