Objective: The fetal-to-neonatal transition is marked by profound cardio-respiratory changes. Infections emerging within the first 48 h after birth may influence early cardiovascular adaptation. We aimed to evaluate the association between early infection/inflammation markers and vital parameters in neonates during the first 15 min after birth. Methods: This is a secondary outcome parameter post-hoc analysis of data derived from a prospective observation study. Preterm and term neonates with cerebral oxygen saturation (crSO2) monitoring (INVOS 5100C) during the first 15 min after birth and available inflammatory markers (C-reactive protein [CRP], leukocytes, immature-to-total neutrophils ratio [IT ratio]) within 48 h after birth were included. Heart rate (HR) and arterial oxygen saturation (SpO₂) were continuously recorded during the first 15 min. Inflammatory markers obtained at 16–24 and 24–48 h after birth were correlated with crSO₂, SpO₂, and HR at minute 5, 10 and 15. Results: Sixty-eight neonates were included (median (IQR) gestational age 34.0 (32.0; 35.9) weeks, birth weight 1900 (1488; 2542) grams). CRP within the first 24 h correlated negatively with crSO₂ (r = −0.314; p = 0.011) and with SpO₂ (r = −0.393; p = 0.001) at minute 15. IT ratio within 24 h correlated negatively with crSO₂ at minute 5 (r = −0.367; p = 0.005), 10 (r = −0.273; p = 0.035), and 15 (r = −0.306; p = 0.013), and with SpO₂ at minute 5 (r = −0.327; p = 0.008). IT ratio at 24–48 h correlated negatively with crSO₂ at minute 15 (r = −0.384, p = 0.012). No significant correlations were observed with HR. Leukocytes within the first 24 h after birth correlated negatively with crSO2 at minute 5 (r = −0.265; p = 0.046). Conclusions: Early inflammatory markers, particularly CRP and the IT ratio, are associated with cerebral and systemic oxygenation during immediate postnatal transition. These findings suggest a potential association between early inflammatory activation and oxygenation dynamics; however, given the observational design and modest correlation strength, the results should be interpreted cautiously and do not allow conclusions regarding causality or underlying mechanisms.