The influence of administration of Lactobacillus paracasei alone and mixture of Lactobacillus paracasei and fructooligosaccharide on faecal bacteria counts in the weanling pigs was investigated. The administration of Lactobacillus paracasei alone significantly decreased Clostridium (p < 0.05) and Enterobacteriaceae (p < 0.05) counts as compared to the control. Lactobacillus paracasei administered in combination with fructooligosaccharide significantly increased Lactobacillus (p < 0.01-p < 0.05), Bifidobacterium (p < 0.05), total anaerobes (p < 0.05), and total aerobes (p < 0.05) counts compared to control group as well as Lactobacillus paracasei group and significantly decreased Clostridium (p < 0.05) and Enterobacteriaceae (p < 0.01) counts compared to control group. The results obtained point out to a synergic effect of the combination of Lactobacillus paracasei and fructooligosaccharide on numbers of bacterial populations observed in the faeces of the weanling pigs.