Microgenetic design or microgenetic method is a scientific method in which the same setting is studied repeatedly in order toobserve possible changes in details. Reviewing the current literature, one can conclude that microgenetic methods havepositive effects of learning in general and language learning in particular. The main objective of the current study was toinvestigate the possible effects of implementing input enhancement techniques using microgenetic methods, on Iranian ESPlearners' conjunction production. To this end, a number of 40 Iranian ESP learners were participated in the study. During thefour-week period of the current study, the participants received the instructions and treatment, two sessions a week and eachsession lasted for an hour. After administering the pre-test before the instruction, using input enhancement techniques, anumber of the conjunctions were presented and taught to the learners in the first session. The data were collected afterinstructional sessions during the first, third, fifth, and seventh weeks through paragraphs focusing on conjunction productionwritten by the participants. The results indicated that, in the course of time, input enhancement techniques using microgeneticmethods, significantly affect Iranian ESP learners' conjunction production.