AIM:To carry out a prospective, multicenter and observational study describing prophylactic strategies [cycle delay, dose-reduction, (G-CSF) prescription] to prevent recurrence of neutropenic events (NE) in patients with solid tumors, and identify potential predictive factors of NE recurrence. PATIENTS AND METHODS:Patients ≥18 years old with an NE in a previous chemotherapy cycle (cycle A) without G-CSF support, followed for four cycles (B to E) were included in the study. NE was defined as any neutropenia grade 1-4, febrile or not, which impacted on subsequent chemotherapy cycles (cycle delay, or reduction, or prophylactic G-CSF). RESULTS:Data of 548 patients were analyzed, 378 (69%) were female, with a mean (SD) age of 61.7 (12.3) years. WHO PS: 0-1: 88.3%, incidence of breast cancer: 40%, metastatic disease: 53.3%. Following the first NE episode, 44.5% of patients had cycle delay, 22.3% dose reduction and 466 (85%) received prophylactic G-CSF. NE recurrence rates were: 21.2% at cycle B, 18.6% at cycle C, 11.5% at cycle D and 12.9% at cycle E. G-CSF support (hazard ratio: 0.32, 0.24-0.43, p<0.001) was associated with lower NE recurrence. Pegfilgrastim seemed to offer the highest protection (hazard ratio; HR=0.23, 95% CI: 0.16-0.32; p<0.001). CONCLUSION:Secondary G-CSF prophylaxis has significant efficacy in reducing the incidence of NE and should be considered as a valuable option.