Background: pediatric –onset SLE (PSLE) is a multisystem autoimmune disease.Recently, the ficolin-2 gene has emerged as a potential candidate gene for susceptibility to SLE. Objectives: the objective of this study was to evaluate the association of the FCN2 gene polymorphisms at the positions -986,-602,-4and SNP c/T located in intron 1, with susceptibility to pSLE in Egyptian children and adolescents. METHODS: this was a multicentre study of 280 patients diagnosed with SLE and 280 patients well matched healthy controls . The FCN2 promoter polymorphisms at -986 G/A ,602G/A, -4A/G and SNP C/T located in intron 1 were genotyped by PCR, while serum ficolin-2 levels were assessed using enzyme linked immunosorbent assay . Results:The frequencies of FCN2GGgenotype and g allele at -986 and -602 positions were significantly more represented in patiens with PSLE than in controls . conversely , the FCN2AA genotype A allele at position -4 were more common in patients than in controls , Moreover , patients carrying the FCN2GG genotype in -986 position were more likely to devolp lupus nephiritis . Conclusion :The FCN2 promoter polymorphisms may contribute to suscebitibilty to PSLE in Egyptian children and adolescents . MOREOVER, the FCN2 GG genotype at position -4 and -986 were associated with low serum ficolin -2 and may constitute risk factors for lupus nephritis in PSLE.