This study mainly aims at evaluating ' English for Libya', English language-learning (ELL) textbook series currently taught at mainstream Libyan primary schools. This involves: (1) identifying– from senior and expert language teachers' perspectives– to what extent the textbook series (primary one to six) conform with the national ELL standards issued by MOE in 2003; (2) exploring the advantages and weaknesses of the series as well as the real problems encountered by primary teachers while teaching it; (3) providing some suggestions and guidelines that should help with improving textbooks delivery in the future. To reach these aims, this evaluative study employed: (a) a standards questionnaire administered – both face-to-face and online - to some expert English language teachers (n=55); (b) focus groups (both face-to-face and online) to enable both pre-service (n=50) and in-service (n=300) EFL primary teachers to discuss freely many issues related to the series (i.e. mainly about strengths and weaknesses) as well as the teaching/learning problems encountered in classrooms; and (c) a selective content analysis assisted by computer as a confirmatory procedure for triangulation purposes – to understand and cross-check participants' accounts based on reviewing all textbooks, and thus provide more accurate and comprehensive results. Findings indicate variability in the achievement of the proposed standards in reality, and present many strengths and weaknesses of textbooks as well as problems related to teaching the series. Finally, based on results, some guidelines for improvement (i.e. improvement framework) are proposed.