The therapeutic value of lipid-lowering drugs in pulmonary vascular disease remains uncertain due to insufficient studies and evidence. This study aims to investigate the causal effects of lipid-lowering drugs (specifically, inhibitors of APOB, CETP, HMGCR, NPC1L1, and PCSK9) on pulmonary vascular diseases using a Mendelian randomization (MR) approach. We utilized summary-level statistics from genome-wide association studies (GWAS) to simulate the exposure to low-density lipoprotein cholesterol (LDL-C) and its outcomes on pulmonary arterial hypertension (PAH), pulmonary embolism (PE), and pulmonary heart disease (PHD). Single-nucleotide polymorphisms (SNPs) within or near drug target-associated LDL-C loci were selected as proxies for the lipid-lowering drugs. Data from the FinnGen cohort and UK Biobank (UKB) were incorporated to enhance the robustness and generalizability of the findings. The inverse variance weighted (IVW) and MR-Egger methods were employed to estimate MR effects. Our MR analysis indicated that LDL-C mediated by NPC1L1 (odds ratio [OR] = 104.76, 95% confidence interval [CI] = 2.01-5457.01,