Acute ischemic stroke (AIS) retains a notable stance in global disease burden, with thrombolysis via recombinant tissue plasminogen activator (rtPA) serving as a viable management approach, albeit with variable outcomes and the potential for complications like hemorrhagic transformation (HT). The platelet-to-neutrophil ratio (P/NR) has been considered for its potential prognostic value in AIS, yet its capacity to predict outcomes following rtPA administration demands further exploration. To elucidate the prognostic utility of P/NR in predicting HT and clinical outcomes following intravenous rtPA administration in AIS patients. Data from 418 AIS patients treated with intravenous rtPA at Thammasat University Hospital from January 2018 to June 2021 were retrospectively analyzed. The relationship between P/NR and clinical outcomes [early neurological deterioration (E-ND), HT, delayed ND (D-ND), and 3-mo outcomes] was scrutinized. Notable variables, such as age, diabetes, and stroke history, exhibited statistical disparities when comparing patients with and without E-ND, HT, D-ND, and 3-mo outcomes. P/NR prognostication revealed an optimal cutoff of 43.4 with a 60.3% sensitivity and a 52.5% specificity for 90-d outcomes. P/NR prognostic accuracy was statistically significant for 90-d outcomes [area under the curve (AUC) = 0.562], D-ND (AUC = 0.584), and HT (AUC = 0.607). P/NR demonstrated an association with adverse 3-mo clinical outcomes, HT, and D-ND in AIS patients post-rtPA administration, indicating its potential as a predictive tool for complications and prognoses. This infers that a diminished P/NR may serve as a novel prognostic indicator, assisting clinicians in identifying AIS patients at elevated risk for unfavorable outcomes following rtPA therapy.