The histone chaperone Spt6 is involved in promoting elongation of RNA polymerase II (RNAPII), maintaining chromatin structure, regulating co-transcriptional histone modifications, and controlling mRNA processing. These diverse functions of Spt6 are partly mediated through its interactions with RNAPII and other factors in the transcription elongation complex. In this study, we used mass spectrometry to characterize the differences in RNAPII interacting factors between wild-type cells and those depleted for Spt6, leading to the identification of proteins that depend on Spt6 for their interaction with RNAPII. In all, eight samples were processed - four genotypes (1. SPT6, RPB3-untagged; 2. SPT6, RPB3-tagged; 3. spt6-1004, RPB3-untagged; 4. spt6-1004; RPB3-tagged) in biological duplicates.