Background <p>This study aimed to identify prognostic factors and treatment patterns at the first recurrence of retroperitoneal liposarcoma (LPS).</p> Methods <p>Medical records of 150 patients who underwent resection for primary retroperitoneal LPS were reviewed. Of the 94 patients with local or distant recurrence, prognostic factors and treatment approaches were retrospectively analyzed.</p> Results <p>At recurrence, 41 patients underwent surgery, 12 received radiation, 23 received chemotherapy, 12 were under active surveillance, and 6 received best supportive care. In univariate analysis, well-differentiated primary tumors predicted better overall survival (OS) compared to dedifferentiated tumors (<i>p</i> = 0.004). Conversely, shorter recurrence-free survival (RFS) after initial surgery, smaller recurrent tumors at treatment, and high neutrophil-to-lymphocyte ratio (NLR) at recurrence were associated with poorer OS (<i>p</i> = 0.0418, 0.007, and 0.0475, respectively). Treatment decisions were influenced by RFS, time from recurrence to treatment, initial tumor differentiation, recurrence site, and multiplicity. Among those who had surgery for recurrence, 29.2% (12/41) showed a change in tumor differentiation. RFS was a significant predictor of this change (<i>p</i> = 0.026). Additionally, NLR at recurrence and the waiting period from recurrence to treatment were significant prognostic factors in surgically treated patients (<i>p</i> = 0.005 and 0.028, respectively).</p> Conclusions <p>RFS, timing of treatment, initial tumor differentiation, and recurrence characteristics influence treatment choices at first recurrence. RFS may predict changes in tumor differentiation, while NLR at recurrence and the waiting period from recurrence to treatment are important prognostic indicators in patients undergoing surgery.</p>