Self-medication is an effort to treat ailments such as flu and cough. The number of
types of cold and cough medicine in the market makes people good at adjusting
the types of medicines and medicines, therefore something is needed for that. In
practice, the limitations of the drug and the user can be a treatment problem (error
treatment). This study uses analytical research methods with cross sectional
design. The sampling technique is Non Probability Sampling using accidental
sampling method. Data were analyzed by Chi-square test using Statistical
Product and Servicer Solution (SPSS) version 23. The results showed that the
level of knowledge of student University Muhammadiyah Puwokerto was 72.67%
included in the good category, and rationality using flu and cough medicine was
90.30% included in the rational category. There is a significant relationship
between knowledge and rationality using cold and cough medicine with as
significantvalueof0.042<(0.05).