Ribosomal preparations (ribosome-component immune modulators [RCIMs]) do not contain attenuated bacteria and, in contrast to live bacterial extracts, which may induce severe side effects, retain immune stimulating activity without infectious capability. This study was designed to profile the tolerability of RCIM by reviewing narratively all randomized, double-blind, placebo-controlled clinical trials and open-label studies as well as data from postmarketing surveillance studies representing >30 million prescriptions. In the various clinical trials, RCIM tolerability in terms of clinical and laboratory parameters was good. There were no significant differences between patients receiving active treatment or placebo in a survey of tolerability results from randomized, double-blind, placebo-controlled studies. Pharmacovigilance analysis does not show a change in the risk profile of RCIM. The only contraindication was correlated with known hypersensitivity to any of the product components. RCIM should not be used in case of acute streptococcal glomerulonephritis, acquired immune deficiency syndrome, severe viral disease, or severe autoimmune disease. Risk associated with the use of RCIM is negligible in recurrent upper and lower airway infections in selected populations, such as children and elderly people.