The present study aimed to investigate the effects of electronic word of mouth (e-WOM) advertising on the sports customers' purchase intention with emphasis on the mediator role of consumer’s involvement. 270 sport customers voluntarily filled out the Bambauer-Sachse and Mangold electronic word of mouth advertising (2011), McQuarrie's consumer involvement (1992) and the Diallo (2012) and Park et al purchase intention (2008) questionnaires. Structural equation modeling (SEM) in software Lisrel 8.51 was used to analyze the data. The results showed that the electronic word of mouth advertising had a significant direct effect on the purchase intention (γ=0.22; p<0.05) and the consumer involvement (γ=0.70; p<0.01). The Findings prove the positive moderation role of involvement on the relationship between electronic word of mouth (e-WOM) advertising and purchase intention. According to results of model analysis the modified model had good fit (CFI=0.94; RMSEA=0.077; χ2/df=2.60). In conclusion, we can say that electronic word of mouth (e-WOM) advertising can have a great impact on the individual knowledge about products and consumer involvement in them, and it can thus affect consumers' purchase intention by provision of a large volume of information in a short time.