In this investigation, fecal specimens from children with diarrhea were collected from four community studies conducted between 1982 and 2019 in Belém, Brazilian Amazon. A total of 234 samples were tested by quantitative reverse transcription polymerase chain reaction (RT‐qPCR) to detect infections by picornaviruses of the Enterovirus (EV), Parechovirus (HPeV), Cosavirus (HCoSV), Kobuvirus (Aichivirus ‐ AiV) and Salivirus (SalV) genera. The positive samples were subjected to different amplification protocols of the VP1 region of the genome, such as nested PCR or snPCR, and were subsequently genotyped by sequencing VP1 and VP3 of the viral genome. Positivity was observed in 76.5% (179/234) of the samples tested using RT‐qPCR for at least one virus, and co‐infection was observed in 37.4% (67/179) of the cases. EV was detected in 50.8% (119/234), HPeV in 29.9% (70/234), HCoSV in 27.3% (64/234), and AiV/SalV in 2.1% (5/234) of the specimens tested by RT‐qPCR. Using nested PCR and/or snPCR techniques, the positivity rates were 94.11% (112/119) for EV, 72.85% (51/70) for HPeV, and 20.31% (13/64) for HCoSV. It was not possible to amplify the samples that were positive for AiV/SalV. Sequencing revealed 67.2% (80/119) EV, 51.4% (36/70) HPeV, and 20.31% (13/64) HCoSV. Forty‐five different types of EV were found among species A, B, and C; HCoSV identified five species, including a possible recombinant strain; all HPeV were identified as belonging to species A, in two samples a possible recombination involving three different strains was verified. This study demonstrated the high circulation and diversity of different types of picornaviruses in fecal samples, including those collected more than 30 years ago. This endorsed the evaluation of important points in the epidemiology of these viruses, such as the presence of co‐infection and the possibility of knowing more about these agents, considering that some were recently described; therefore, their detection in older samples can provide more data about their ancestry.