A tuition-free, vocational, English as a second language (ESL) program offered at a large community college suffers from high attrition as well as student dissatisfaction with curriculum. The purpose of this quasi-experimental, longitudinal study was to assess the effectiveness of a specific ESL curriculum supplement as an intervention to alleviate the twin problems of high attrition and student dissatisfaction in this program. Two high-level ESL classes were selected for comparison. The study sample consisted of 83 adult ESL students administratively pre-assigned to classes in the highest level, based on advancement from lower levels (or on placement tests, if new to the program). 42 students had enrolled in the class designated as the experimental group and received the new curriculum supplement, while 41 students had enrolled in the class designated as the control group and received only the standard curriculum. The curriculum intervention involved the implementation of a daily regimen of lessons featuring scripted, situational dialogues created in advance of the study by this researcher. In these situational dialogue activities, each student would pair off with a classmate, playing roles in simulations of real-life situations. The study sought to discover whether the implementation of this highly interactive, structured dialogue technique would result in increases in attendance, retention, and student satisfaction while simultaneously yielding a positive impact on standardized test scores. Test scores, attendance, and retention were compared between groups. Both groups also completed questionnaires both at the beginning and end of the term soliciting both qualitative and quantitative feedback regarding their satisfaction with their curriculum. The findings of the study indicated that the quantitative differences between the two groups in several of the outcomes metrics were statistically negligible; however, qualitative data obtained from the experimental group indicated that a great majority of students were highly satisfied with the dialogue methodology and derived substantial benefits from it. These benefits included a greater facility for practicing speaking and an opportunity to assimilate valuable idiomatic phrases and new vocabulary. The study recommends that adult vocational ESL classes make further use of interactive situational dialogue methodologies as a means of heightening student satisfaction. The following are appended: (1) Recommended Procedure for Teaching the Dialogues; (2) Student Satisfaction Survey 1; (3) Student Satisfaction Survey 2; (4) Student Data Form; (5) Excerpt from "Side by Side: Student Book 4"; (6) Excerpt from "Focus on Grammar Book 4"; (7) Excerpt from "Everyday Dialogues in English"; (8) Dialogue Lessons. (Contains 1 table and 2 figures.