Infant colic is a common condition of unknown pathogenesis that brings frustration to families seeking for effective management. Accumulating evidence suggests that some single strains of lactobacilli may play a positive dietary role in attenuation of colic in exclusively breastfed infants. The objective of this study was to evaluate a mixture of two Lactobacillus strains in decreasing infant cry and fuss in this population. Infants aged 4-12 weeks received L. rhamnosus 19070-2 and L. reuteri 12246 in a daily dose of 250 × 106 CFU, 3.33 mg of fructooligosaccharide, and 200 IU of vitamin D3 (84 infants, probiotic group) or just vitamin D3 (84 infants, control group) for 28 days. Cry and fuss time were measured with validated Baby`s Day Diary on days 0 and 28. At baseline, mean (SD) duration of cry and fuss time was comparable in the probiotic and control groups: 305 (81) vs. 315 (90) min., respectively (p = 0.450). On day 28, mean cry and fuss time became statistically different: 142 (89) vs. 199 (72), respectively (p < 0.05). Mean change in cry and fuss time from day 0 through day 28 was -163 (99) minutes in the probiotic and -116 (94) minutes in the control group (p = 0.019). Our findings confirm that lactobacilli decrease cry and fuss time and provide a dietary support in exclusively breastfed infants with colic.