Introduction: Dextrans are D-glucose homopolysaccharides made by bacteria. There are several different bacterial species that produce these polysaccharides. Dextran is used as an adjuvant, drug carrier emulsifier, carrier, and stabiliser in the food, pharmaceutical, and chemical sectors, Nano gel. The aim of the study is to isolate Lactobacillus spp. from clinical sources, to identify the dextran production yield in Lactobacillus spp, and to reach the optimal growing parameters to discover the optimal dextran growth conditions. Methodology: 50 isolates of Lactobacillus spp. were gathered from different medical facilities in Baghdad City, 21 isolates came from healthy women's vagina (16 Lactobacillus plantarum, 5 Lactobacillus acidophilus), and 29 isolates came from samples of infant stool (15 Lactobacillus plantarum, 4 Lactobacillus acidophilus, and 10 Lactobacillus gasseri). All isolates were examined for dextran production using mucoid and spectrophotometric methods. Results: Lactobacillus acidophilus that was isolated from the genital tract of healthy women produced greater dextran. The results shows that the optimum conditions for dextran production that were investigated, there are several parameters play important roles to reach the optimal conditions, including, different natural carbon sources, nitrogen source, temperature, sucrose concentration, incubation time, pH, inoculum size. Conclusions: he optimum conditions for production were at 37 ºC for 48h at pH 5.5 with 4 % inoculum size and 6 g/ 100ml sucrose concentration with 6% best nitrogen source beef extract and the best natural carbon source for dextran production was dates.