Background Marmosets are susceptible to dengue virus (DENV) infection. However, blood parameter data and clinical signs of DENV-infected marmosets are limited. Methods Blood hematological and serum biochemical values were obtained from twelve DENV-inoculated and four mock-infected marmosets. Additionally, body temperature and activity level were determined. Results Five DENV-inoculated marmosets demonstrated thrombocytopenia, nine demonstrated leucopenia, and five demonstrated an increase in the levels of AST, ALT, LDH, and BUN. Additionally, seven DENV-inoculated marmosets demonstrated clinical signs including fever and decreases in activity. None of the four mock-inoculated marmosets demonstrated changes in either hematological or biochemical parameters. Conclusions Marmosets inoculated with DENV exhibited clinical signs and changes in hematological and biochemical parameters. The results suggest that blood parameter data and clinical signs could potentially be useful markers for understanding the progress of DENV infection in studies using marmosets.