The current study aimed at investigating teaching collocations and its effect on further developments in speaking fluency. To achieve this, a total number of 60 EFL learners who were learning English at a language institute in Talesh served as sampling. A Michigan Test of English Language Proficiency (1997) was used to ensure the homogeneity of the participants. That is, those language learners who met the selection criterion, i.e., performed one standard deviation above and below the mean on the proficiency test were divided into two classes (N=38). Then, they were randomly divided into two groups: one experimental group (N=19) and one control group (N=19). Participants in experimental group were provided with teaching collocations; however, the control group underwent traditional instruction of lexical items. It was assumed that teaching collocations is an efficient way to improve the learner’s language speaking fluency. After 12 weeks of treatment, an IELTS speaking task was given to the both groups and an independent t test was used to compare means of test scores between groups. Results indicated that the experimental group outperformed the control group, i.e., collocation instruction was an effective approach for further improvement of EFL learners’ speaking fluency.