A different chemical nature of PET/cotton fibers hinders to attain solid shade during the coloration process. To overcome this problem in current the attempt, surface functionalization of PET/cotton fabric by simple and cost effective sol-gel technology was investigated. By this simple coating method, different anchor sites were introduced onto the PET/cotton fabric surface such as amine, epoxy or hydroxyl. Incorporation of such groups was conducted using two different alkoxysilanes, namely 3-Aminopropyltriethoxysilane (APTES) or 3-Glycidyloxypropyltrimethoxysilane (GPTMS) as coupling agents for C.I. reactive blue 5 and C.I. acid blue 80 dyes. The sol-gel synthesis reactions of used alkoxysilanes were preceded under either acidic or basic condition. The chemistry and morphology of APTES and GPTMS modified PET/cotton surface were studied by utilizing some surface sensitive techniques such as streaming potential measurements, ATR-FTIR, X-ray photoelectron spectroscopy (XPS), time-dependent contact angle measurements as well as scanning electron microscopy (SEM). In addition, color strength and fastness tests of the prints were examined to test the effectiveness of the fabric surface modification. It was observed that the isoelectric point value of PET/cotton fabric coated with base-hydrolyzed APTES is shifted toward higher pH value in comparison with PET/cotton fabric coated with base-hydrolyzed GPTMS. Furthermore, the hydrophobicity of sol-gel modified PET/cotton fabric was increased. The results also presented that the PET/cotton blend fabrics after treatment with base-hydrolyzed APTES showed improvement in K/S value and fastness properties.