The comparative analysis of results of complex clinic-laboratory examination of 156 children at the age from 1 мес till 14 years, with a salmonellosis (n=39) and a salmonellosis, associated with a lambliasis (n=117), which were in intestinal infections clinic the Research Institute of Children Infections (Saint-Petersburg) to the period with 2008 on 2010 are presented in the article. It is established that the basic originators admixed salmonella-lambliosis infections at children till 3th years are Salmonella of group B, at children is more senior 3th years – Salmonella of group D (Salmonella enteritidis). Leading diagnostic criteria for statement of the early etiological diagnosis admixed salmonella-lambliosis infections at children are defined. The received results confirm that salmonellosis infection, mixt with a lambliosis, at children is the admixed form of the infection caused by two originators (salmonella and lamblia), and is defined by their quantitative parity in an ecological niche, character of mutual relations, in particular, adhesive activity of salmonella in relation to cysts of lamblia, and also clinico-anamnestic and clinico-laboratory features.