This research studied the potential and efficiency of tamarind kernel powder as a thickener for pigment printing on cotton fabric in comparison with the commercial synthetic thickener. Two kinds of tamarind seed were studied. Both of tamarind seeds contained about 30% based on dry weight of outer seed coating and 70% of dry weight of tamarind kernel powder. The approximate composition of tamarind kernel powder were 2.39 – 3.19% fat, 16.43 – 17.07% protein, 1.20 – 1.68% crude fiber and 3.42-3.74% moisture based on weight of tamarind kernel powders. Two different extraction techniques were studied viz., boiling in water and using microwave. Tamarind kernel powder extracted by microwave method was suited for use as a thickener rather than those obtained by boiling in water method. As the tamarind kernel powder from microwave method was easier dissolved and the printing paste was smoother than those from boiling in water. The optimum concentration of tamarind kernel powder for pigment printing on cotton was 5% tamarind kernel powder obtained from the seed in relatively round shape and smooth surface because the color yield and rubbing fastness was similar to the commercial synthetic thickener.