Background and purpose The effect of the triglyceride (TG) to high‐density lipoprotein cholesterol (HDL‐C) ratio (TG/HDL‐C) on clinical outcomes of acute ischaemic stroke (AIS) patients is unclear. This study sought to determine whether the TG/HDL‐C ratio in AIS patients is associated with worse outcomes at 3 months. Methods Acute ischaemic stroke patients who were admitted from 2011 to 2014 were enrolled in this study. TG, total cholesterol (TC), HDL‐C and low‐density lipoprotein cholesterol (LDL‐C) were collected on admission. Three end‐points were defined according to the modified Rankin scale (mRS) score at 3 months after symptom onset (excellent outcome, mRS 0–1; good outcome, mRS 0–2; and death, mRS 6). Results In all, 1006 patients were included (median age 68.5 years; 58.2% male). Higher TG, non‐HDL‐C and TG/HDL‐C were strongly associated with the three end‐points after adjustments: excellent odds ratio (OR) = 1.39, OR 1.89 and OR 2.34, respectively and good (OR 1.48, OR 2.90 and OR 4.12) outcomes, and death (OR 0.59, OR 0.29 and OR 0.26). According to receiver operating characteristic (ROC) analysis, the best discriminating factor was a TG/HDL‐C ≥ 0.87 for excellent outcomes area under the ROC curve (AUC) 0.596; sensitivity 73.3%; specificity 42.7% and non‐death (AUC 0.674; sensitivity 67.8%; specificity 60.6%) as well as a TG/HDL‐C ≥ 1.01 for a good outcome (AUC 0.652; sensitivity 61.6%; specificity 63.2%). Patients with a TG/HDL‐C < 0.87 had a 2.94‐fold increased risk of death (95% confidence interval 1.89–4.55) compared with patients with a TG/HDL‐C ≥ 0.87. Conclusions A lower TG/HDL‐C was independently associated with death and worse outcome at 3 months in AIS.