Our study was descriptive, using a quantitative approach, with a questionnaire inspired by Salamé Pascale to assess knowledge, and a questionnaire by Donald Morisky (MMAS: Morisky Medication Adherence Scale) on therapeutic compliance. The sample comprised 64 patients with a mean age of 58.08, predominantly female (76.6%). The average level of overall knowledge was 73.44%. Only 34.38% had an average level of compliance. The low rate of good compliance among our patients reflects the inadequacy of therapeutic education carried out at the start of treatment. The implementation of a standardized education program for all patients could improve patient knowledge and systematically offer patients treated with levothyroxine a therapeutic information session on their treatment.