In response to diverse genotoxic stimuli, eg., UV and cisplatin, the mitogen-activated protein kinases ERK1/2, JNK1/2, and p38a/ß become rapidly phosphorylated, and in turn activate multiple downstream effectors that modulate apoptosis and/or growth arrest. Furthermore previous lines of evidence have strongly suggested that ERK1/2 and JNK1/2 participate in global-genomic nucleotide excision repair, a critical antineoplastic pathway that removes helix-distorting DNA adducts induced by a variety of mutagenic agents including UV light. To rigorously evaluate the potential role of mitogen-activated protein kinases in global-genomic nucleotide excision repair, various human cell strains (primary skin fibroblasts, primary lung fibroblasts, and HCT116 colon carcinoma cells) were treated with highly-specific chemical inhibitors which, in response to UV, (i) abrogated the capacities of ERK1/2, JNK1/2, or p38a/ß to phosphorylate specific downstream effectors and (ii) characteristically modulated cellular proliferation, clonogenic survival, and/or apoptosis. A highly-sensitive flow cytometry-based nucleotide excision repair assay recently optimized and validated in our laboratory was then employed to directly demonstrate that the kinetics of UV DNA photoadduct repair are highly similar in mock-treated vs. mitogen-activated protein kinase inhibitor-treated cells. These data on primary and tumour cells treated with pharmacological inhibitors were fully corroborated by repair studies using (i) shRNA-mediated knockdown of ERK1/2 or JNK1/2 in human U2OS osteosarcoma cells, and (ii) expression of a dominant-negative p38a mutant in human primary lung fibroblasts. Our results provide solid evidence for the first time, in disaccord with a burgeoning perception, that mitogen-activated protein kinase signalling does not influence the efficiency of human global-genomic nucleotide excision repair.