Seven mixed arsenic(III) bis(dimethyldithiocarbamato) derivatives of type [(CH3)2NCS2]2AsL where, L = OOCC6H5, OOCCH3, OOCC6H4(OH), SC6H5, SCH2COOH, SOCCH3 and S(C6H4)COOH have been synthesized and characterized by various physicochemical [elemental analysis (C, H, N, S & As), molecular weight and melting point determinations], spectral [UV–Vis., FTIR, NMR (1H and 13C)], thermal [TGA and DTG], powder XRD studies. The presence of FT-IR band at 1064–1095 cm−1 due to thiocarbonyl moity and 13C NMR signal in the range 192.56–198.59 ppm due to -NCS2 carbon resonance have indicated anisobidentate mode of bonding of dithiocarbamate group, alongwith this FT far-IR bands observed due to the υ(As–O) and υ(As–S) vibrations in the region 530–532 cm−1 and 302–333 cm−1 respectively, confirm the bonding of arsenic(III) to oxygen and sulfur. Thus, on the basis of results obtained by above spectral techniques, it may be concluded tentatively that, arsenic(III) derivatives (compound 1–7) adopted a distorted octahedral geometry with lone pair of electrons occupying one of the corner of octahedra. Powder XRD studies revealed that these derivatives have nano ranged particle size (5.72 and 16.29 nm) with lower symmetry (monoclinic) crystal system along with unit cell volume (1731 and 1764 Å3). Thermal studies reveal that arsenic(III) bis(dimethyldithiocarbamato) thiosalicylate (compound 7) gives arsenic sulfide as a final decomposition product, which have various potential applications. Antimicrobial screening test showed enhanced activity than free ligands and standard drugs.