The Nesotriatoma genus consists of the species N. flavida N. bruneri and N. obscura, forming the Flavida complex. Variation in the size and morphological differences intraspecific of N. flavida led to the description of N. bruneri. Two years later, the same author proposed the synonymization of N. bruneri with N. flavida. Only in 1981 the specific status N. bruneri was recovered by means of morphological analysis of the genitalia. However, recently by genetic analysis, it was suggested that N. bruneri and N. flavida should be again synonymized. As Chagas disease has no cure, the main way to minimize the incidence of this disease is by vector control. Thus, grouping biological data from these hematophagous insects can assist in the development of vector control programs and mainly assist in taxonomic issues of synonymization. Thus, this paper describes spermatogenesis of N. bruneri. Three adult N. bruneri males were cytogenetically analyzed. The meiotic behavior observed for N. bruneri was very similar to that observed for the triatomine species with 23 chromosomes: during prophase, chromatin compaction was observed, the chromocenter composition was characterized (X1, X2 and Y), and the species karyotype was confirmed as 2n = 23 (20A + X1X2Y), as it was observed for N. flavida. Moreover, it was possible to observe anaphase and telophase. Thus, this study describes reproductive aspects of N. bruneri in order to contribute to the biological knowledge of these insects of epidemiological importance. Furthermore, this corroborates the synonymization of N. bruneri with N. flavida.