Using a foreign language is one of the greatest talents anyone can have. However, if it is not required to use a foreign language in everyday life, the risk of losing proficiency is big. There are several practical strategies that can be helpful in a foreign language setting. Hence, this study mainly aimed at identifying the English proficiency retention strategies which were adopted by Iranian adult advanced English language learners. It also aimed at investigating the effect of gender and education level on second language proficiency retention.