Immobilized titanium dioxide (TiO2) nanoparticles on flat sheet polymeric membranes have been found effective for fouling reduction in recent researches. The main challenge in this field is to obtain ultrafine and stable nanodispersions. In this study, composite polyvinylidene fluoride/TiO2 (PVDF/TiO2) ultrafiltration membranes were prepared via phase inversion and colloidal precipitation method. Stable TiO2 suspensions were prepared using sodium polymethacrylate as dispersant and sonication without altering of the coagulation bath pH. The effect of different concentrations of TiO2 nanoparticles in the coagulation bath was also investigated. The membrane morphology (distribution of nanoparticles on the membrane surface) was observed by scanning electron and atomic force microscopy. Properties of the neat and the composite membranes were also characterized using energy dispersive X-ray spectroscopy and contact angle and membrane porosity measurements. The neat and the composite membranes were further investigated in terms of bovine serum albumin rejection and flux decline in cross flow filtration experiments. The results showed that the PVDF/TiO2 composite membrane using dimethylacetamide/triethyl phosphate as solvent and 0.05 g/L of TiO2 in the coagulation bath exhibits improved antifouling properties. POLYM. ENG. SCI., 59:E422-E434, 2019. (c) 2018 Society of Plastics Engineers