Updated project metadata. Human follicular fluid (hFF) is a natural environment of oocyte maturation, and some components of hFF could be used to judge oocyte capability for fertilization and further development. In our pilot small scale study three samples from four donors (12 samples in total) were analyzed to determine which hFF proteins/peptides could be used to differentiate individual oocytes and which are patient specific. Ultrafiltration was used to fractionate hFF to High Molecular Weight (HMW) – proteome (>10kDa) and Low Molecular Weight (LMW) – peptidome (<10 kDa) fractions. HMW and LMW compositions were analyzed using LC-MS in SWATH data acquisition and processing methodology. In total we were able to identify 158 proteins, form which 59 were never reported before as hFF components. 55 (45 Never reported before) proteins were found by analyzing LMW fraction, 67 (14 never reported before) were found by analyzing HMW fraction, and 36 were identified in both fractions of hFF. We were able to perform quantitative analysis for 72 proteins from HMW fraction of hFF. We found that concentrations of 18 proteins varied substantially among hFF samples from single donors and those proteins are promising targets to identify biomarkers useful in oocyte quality assessment.