Aphasia is defined as "the loss of ability to communicate orally, through signs, or in writing, or the inability to understand such communications; the loss of language usage ability." Aphasia is present in 21~38% of acute stroke patients and is associated with high morbidity, mortality and expenditure. The evidence based challenges was described that occurred when carrying out systematic reviews of language therapy for aphasia following stroke. Language therapy in treating aphasia is efficacious when provided intensely for the first 3 months. There is strong evidence that computer-based aphasia therapy results in improved language skills. Constraint induced language therapy can result in improved language function and everyday communication in chronic aphasics. Treatment with rTMS may be associated with improved naming performance in patients with non-fluent, chronic aphasia. But, further investigation is required. Several placebo-controlled trials suggest that piracetam is effective in recovery from aphasia when started soon after the stroke. Drugs acting on catecholamine systems (d-amphetamine) have shown varying degrees of efficacy when combined with language therapy. Data from single-case studies, case series and an open-label study suggest that donepezil may have beneficial effects on chronic poststroke aphasia. Preliminary evidence suggests that donepezil is well tolerated and its efficacy is maintained in the long term. Significant language and communication gains have been demonstrated following the use of memantine in conjunction with constraint-induced language therapy.