Although T lymphocytes are not infected by DENV and appear not to be infected by ZIKV 34, the impact of each one and of the DENV/ZIKV coinfection seem to affect their function. To address this investigation, we attempted to analyze some features of CD4+ and CD8+ T cell response in PBMC from patients in a cohort of DENV only, ZIKV only and DENV/ZIKV coinfected patients. Our work began with extensive fieldwork in the Midwest region of Brazil in 2016. There, 134 suspected cases of dengue or zika with an acute febrile illness were recruited, including those with by at least two of the signs and symptoms (headache, myalgia or arthralgia, rash, pruritus, retro‐orbital pain, and prostration). Methods of serology and molecular biology have been designed to diagnose the etiologic agent. Of the suspected cases, 6% of them confirmed ZIKV alone, 50% DENV, 22% were coinfected DENV/ZIKV, the others chikungunya, coinfections or not confirmed cases. At this point we realize that we did not have a larger number of samples with zika alone (Azeredo et al. data in submission). Therefore, we analyzed small numbers of individuals in each studied group to match ZIKV‐infected patients’ number, even though aware of the possible impact on dispersion of variables such as age, gender, and others because of a reduced number of donors. Despite that, we could report for the first time some aspects of DENV/ZIKV coinfection and compare then to DENV and ZIKV only infections, as well as healthy donors. Herein, our data reported from 17 well‐characterized patients infected by DENV, ZIKV or DENV/ZIKV and 4 healthy donors.