Seventy-three samples of acute wound fluid were collected from 47 patients during the first 3 postoperative days (POD) following mastectomy for cancer (n=47 on POD-1, n=19 on POD-2, and n=7 POD-3). Samples were analyzed by enzyme-linked immunosorbent assay for growth factor levels (epidermal [EGF], platelet-derived [PDGF], basic fibroblast [bFGF], transforming growth factor-?1 [TGF-?1], vascular endothelial [VEGF]), interleukin-6 (IL-6), matrix metalloproteinases (MMPs-2, -3, -9), and the tissue inhibitor of metalloproteinase 1 (TIMP-1). The levels of EGF, bFGF, PDGF, and interleukin-6 peaked on POD-1, with a significant decrease by POD-3, while total and active MMP-2, MMP-3, and tissue inhibitor of metalloproteinase 1 showed a progressive and significant increase from days 1 to 3. The wounds that later developed an infection (11%) were found to have a significantly lower PDGF and EGF on day 1 (PDGF, median 169 pg/mL [range, 86–2,595]) than the noninfected wounds (2,098 [17–66,506] p<0.05, Mann–Whitney U-test). Sixty-two percent patients developed a seroma and the levels of bFGF were significantly less in these patients (441 pg/mL [45–4,108]) than in those patients where there was no seroma (807 [245–3,133] p<0.05). The levels of certain growth factors in acute wound fluid may be important markers for wound outcomes.