Parvovirus B19 (B19V) was first detected in Manaus, Amazonas, in 2005 through serological testing. This study reports the occurrence of B19V in samples from patients suspected of having dengue infection from Itacoatiara, Manacapuru, and Tefé. We used molecular and serological techniques to examine samples from patients negative for malaria and dengue from municipalities in Amazonas between 2013 and 2018. B19V DNA was detected in 104 samples, with more positive cases between January and July in the age groups of 0-19 and 20-59 years; B19V equally infected male and female patients. Twenty patients were positive for anti-IgM B19V antibodies. The largest number of positive cases was identified in adults aged 20 to 50 years. Among these, 10 patients also had IgM/DNA B19V antibodies. Our findings confirm B19V as an etiological agent of febrile syndrome in adults and children, emphasizing the importance of differential diagnosis. The simultaneous presence of anti-IgM antibodies and viral DNA highlights the need for additional clinical and laboratory studies of these patients.