Single orthorhombic phase Bi(2-x)Ag(x)S(3) (x = 0-0.07) bulk materials were prepared by combining mechanical alloying (MA) with spark plasma sintering (SPS) technique. The microstructure and electrical transport properties were investigated with a special emphasis on the influence of Ag content. All the samples have a high density (91.1-95.9%) and homogeneous grains of about 100-500 nm. Optimizing the Ag content greatly improves the electrical conductivity and leads to a peak value of 2.8 x 10(3) S m(-1) at 523 K for the Bi(1.99)Ag(0.01)S(3) composition. The absolute value of Seebeck coefficient shows an inversely varying trend to the electrical conductivity with Ag content, whereby a power factor at 523 K by adjusting Ag content is enhanced from 91 mu W mK(-2) for Bi(2)S(3) to 235 mu W mK(-2) for Bi(1.99)Ag(0.01)S(3). The thermal conductivity of Bi(2-x)Ag(x)S(3) ranges from 0.48 to 0.73 W mK(-1), which is lower than the reported values of Bi(2)S(3) compounds. An enhanced maximum ZT value 0.25 is achieved at 573 K for the Bi(1.99)Ag(0.01)S(3) sample, which is the highest value in Bi(2)S(3) system in literature. The present work reveals that the non-toxic and cheap Bi(2)S(3) based compound is a promising candidate for the thermoelectric applications. (C) 2011 Elsevier B.V. All rights reserved.