This study aimed to investigate the relationship between Kolb's learning styles and learning slang among Iranian EFL students with a gender-based focus. To this end, 63 EFL students of Tehran University were selected as the participants of the study out of 70 through the proficiency test by simple random sampling. The participants were both genders--27 males and 36 females aged between 18 and 25 in 2017-2018. Using descriptive statistics, correlation, regression and t-test, the data were analyzed. The results of the study indicated a high, significant and positive regression of Kolb's learning style. The highest correlation between Kolb's learning styles and learning American slang was related to the Concrete Experience (CE) and the weakest one was related to the Abstract Conceptualization (AC). The results of the correlation demonstrated positive, significant and high correlation between the Kolb's (2005) learning styles and slang learning. Likewise, the study showed the highest correlation between the experiential learning styles (Concrete Experience, CE) and the slang learning. Meanwhile, the study showed non-significant correlation either between gender and slang learning or between gender and learning styles. The implication is that the teacher trainers may include fostering the beneficial learning styles in their lesson plan in order to improve the teachers' teaching.