We analyzed whether Spanish-speaking children with Specific Language Impairment(SLI) showed deficits in lexical-semantic processing/organization, and whetherthese lexical measures correlated with standardized measures of languageabilities. Fourteen children with Typical Language Development (TLD) and 16age-matched children with SLI (8;0–9;11 years) participated. In aLexical Decision (LD) task with implicit semantic priming, children judgedwhether a given speech pair contained two words (semantically related/unrelated)or a word-pseudoword. Children received a comprehensive language and readingtest battery. Children with TLD exhibited significant semantic priming; theywere faster for semantically related word pairs than for unrelated(p < .001) and than for word-pseudoword pairs(p < .0002). The group with SLI did not exhibitsignificant semantic priming, despite showing more variability. Children withSLI made significantly slower LDs [F(1, 26) = 4.61,p < .05, partial η2= .15] and more errors [F(1, 26) = 4.16,p < .05, partial η2= .13] than children with TLD. Mean response time across all LDconditions and the receptive vocabulary (PPVT-III) were significantly negativitycorrelated for children with SLI (r =–.71, p = .004). Children with SLI,especially those with the poorest language scores, showed a semantic-lexicaldeficit and a weakness in lexical-semantic association networks. Theirperformance on the LD task was significantly slower and poorer than for childrenwith TLD. Increasing a child’s vocabulary may benefit lexicalaccess.