Aims: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor is a powerful low density lipoprotein cholesterol (LDL-C)-lowering therapy, but this drug is expensive. This study aimed to describe the real-world treatment conditions in patients initiating PCSK9 inhibitor in Taiwan.Methods: This was a multicenter, retrospective, and observational study. The clinical characteristics, baseline lipid-lowering therapy, and changes in the lipid profile of patients receiving PCSK9 inhibitor treatment were obtained from 11 major teaching hospitals in Taiwan.Results: A total of 296 patients (age 57±13 years, male 73%) who received PCSK9 inhibitor treatments (73.3% alirocumab and 26.7% evolocumab) from 2017 to 2021 were included. Among the patients, 62.8% had history of coronary artery disease, and 27.7% had myocardial infarction. High intensity statin (HIS) monotherapy or HIS＋ezetimibe treatment was used in 32.5% when initiating PCSK9 inhibitor treatment. Among alirocumab users, 21.2% received 75 mg every 3 to 4 weeks, whereas among evolocumab users, 8.9% received 140 mg every 3 to 4 weeks. Almost all the non-standard-dosing PCSK9 inhibitors were paid by the patients themselves but were not reimbursed by the Taiwan National Health Insurance. Overall, the LDL-C levels at baseline and 12 weeks after treatment were 147.4±67.4 and 69.7±58.2 mg/dL (p＜0.01), corresponding to a 49.6%±31.8% LDL-C reduction.Conclusions: In the real-world practice in Taiwan, the LDL-C reduction efficacy of PCSK9 inhibitors was slightly lower than that reported in the clinical trials. The use of non-standard-dosing PCSK9 inhibitors was not uncommon in Taiwan.