This Project examined the impact of advertising on consumer patronage concerning Doyin Pharmaceutical Nigeria Limited as a case study to determine the difference between the variable- Advertising (Independent variables) and the consumer's patronage (Dependent variables). The persistent competitive nature of the business environment and the need to evaluate the influence of advertising on sales achievement costs and its benefits. The researcher reviewed some textbooks by reputable authors, along with some relevant journals and other related published works. The primary and secondary sources of data collection, that is, the textbooks, journals, and the questionnaire, were used to gather information. The participants were drawn from Doyin Pharmaceuticals Nigeria Limited. A questionnaire was designed to collect data from the respondents for easy analysis, and due to time constraints, the sampling technique was used to represent the population. Of the 100 questionnaires administered, 90 copies were recovered, representing the sample size. Based on this number of respondents and their responses, the data collected were presented and analysed using the simple percentage and chi-square methods. The data was collected using a 2-point scale, Yes and No. Since the questionnaire was based on an ordinal scale, the result revealed a significant relationship between advertising and consumer patronage. Therefore, companies are encouraged to recognize the benefits of embarking on promotional strategies, particularly advertising.