Objective. To evaluate the impact of two microbial additives on the productive behavior, zoometric, incidence of diarrhea and mortality of post-weaning piglets. Materials and methods. A total of 120 piglets (Duroc / Yorkshire / Landrace) were used, divided into three groups of 40 animals each, control (T1); microbial preparation A (T2) and microbial preparation B (T3). The T2 contained Lactobacillus acidophilus, Lactobacillus bulgariccus y Streptoccus thermophilus. The T3 was composed of microorganisms of T2 plus Saccharomyces cerevisiae and Kluyveromyces fragilis (L-4 UCLV). We used a completely randomized design where we evaluated, live weight, daily mean gain, height: raised at the cross, raised to the rump, body length, for both sexes and diarrheal incidence and mortality. Results. Live weight in the offspring (males and females) consuming microbial additives were higher and of these were higher in T3. Regarding the average daily gain, the largest increases were found in T3 group. Elevated to the cross, raised to the rump and length of body was greater (p<0.05) in T2 and T3 at birth; while at the end of the study in T3 it was superior. The incidence of diarrhea was higher (p<0.05) in the control group. The animals of the groups that consumed microbial preparation had no deaths during the study. Conclusions. The use of the microbial additives evaluated had a positive effect on the productive and zoometric behavior of the piglets. In addition, the reduction of the incidence of diarrhea and mortality of the animals was achieved.