The Anaphase-Promoting Complex (APC) is a multi-subunit E3 ubiquitin ligase that targets proteins for degradation to drive cell cycle events. This is achieved by association with co-activator proteins Fizzy (CDC20) or Fizzy-Related 1 (FZR1). A role for the APC during mammalian meiosis is beginning to emerge with recent studies implicating the complex in the processing of the piRNA family of small non-coding RNAs during spermatogenesis. piRNAs and their associated PIWI proteins, (murine homologs: MIWI, MILI and MIWI2) are differentially expressed during spermatogenesis, and are thought to play an important role primarily in transposin silencing. To confirm which APC co-activator is responsible for degradation of PIWI proteins in the mouse, we performed immunostaining, immunoprecipitation and proximity ligation assays upon isolated germ cells. Double immunostaining of isolated pachytene spermatocytes and round spermatids showed colocalisation of PIWI and FZR1 in these cells. This was also observed in pachytene spermatocytes of adult mouse testis sections. Additionally, we detected an interaction between FZR1 and PIWI in pachytene spermatocytes and round spermatids, and confirmed that there was no interaction between the co-activator protein CDC20 and PIWI in round spermatids. Future studies using spermatocyte-specific knockout of FZR1 will help to further elucidate the importance of APC-FZR1 mediated PIWI proteolysis during spermatogenesis.