The purpose of this study was to explore the precise role and mechanism of p38 inhibiting cutaneous squamous cell carcinoma associated lincRNA (PICSAR) in CSCC. The expression levels of PICSAR, microRNA-125b (miR-125b) and yes-associated protein1 (YAP1) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis and invasion were evaluated by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, transwell assay, respectively. The interaction between miR-125b and PICSAR or YAP1 was predicted by bioinformatics software and confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Western blot was employed to detect the protein expression of YAP1. The mice xenograft model was established to investigate the role of PICSAR in vivo. PICSAR was upregulated in CSCC tissues and cells. PICSAR knockdown inhibited cell proliferation and invasion and induced apoptosis in CSCC cells. Moreover, miR-125b could directly bind to PICSAR and its inhibition reversed the effect of PICSAR knockdown on proliferation, invasion and apoptosis in CSCC cells. In addition, YAP1 was a direct target of miR-125b and its overexpression attenuated the anti-cancer role of miR-125b in CSCC cells. Furthermore, YAP1 expression was positively regulated by PICSAR and negatively regulated by miR-125b. Besides, interference of PICSAR suppressed tumor growth by upregulating miR-125b and downregulating YAP1. PICSAR knockdown suppressed cell proliferation and invasion and promoted apoptosis in CSCC cells by regulating miR-125b/YAP1 axis, providing new sights for treatment of CSCC. • Knockdown of PICSAR suppressed cell proliferation and invasion and facilitated apoptosis in CSCC cells. • MiR-125b was a target of PICSAR and its inhibition reversed the effects of PICSAR knockdown in CSCC cells. • YAP1 was a downstream target of miR-125b and its overexpression abated the anti-tumor effect of miR-125b in CSCC cells. • PICSAR acted as a ceRNA via sponging miR-125b to modulate YAP1 expression in CSCC cells. [ABSTRACT FROM AUTHOR]