Writing is one of the most difficult and neglected skills for EFL learners. Gamification, the use of game elements to increase user experience and interest in non-game content, can be used to deal with writing anxiety which is considered as a hindering affective factor in successful language learning. Within this scope, this study aims to investigate the effect of the online gamification tool 'Edmodo' on EFL learners' writing anxiety levels. The experimental design, one of the quantitative methods, was preferred. Data were collected through a background questionnaire and the Second Language Writing Anxiety Scale, involving 22 items scored on a five-point Likert response scale. Data were analysed with the Statistical Package for Social Sciences software. The results showed that the students who completed the activities and who were graded through Edmodo had significantly lower anxiety levels than the students using the traditional pen and paper.