Medication therapy management (MTM) refers to the activities provided by pharmacists that patients recognize as evidence of care being provided. It encompasses the services that patients value and consider valuable. Many developing nations like Yemen have had poor implementation of MTM services. Thus, this research assessed the Knowledge, Attitudes, and Practices (KAP) of Yemen pharmacists regarding MTM. We conducted a cross-sectional study using a self-administered questionnaire among pharmacists in Sana’a, Yemen. They were recruited through convenience sampling. The alpha level of 0.05 was used to determine statistical significance. Four hundred and sixty-one (461) pharmacists completed the questionnaire. About 70% were working in community pharmacies and 57.3% had (1–5) years of experience in pharmacy practice. The younger pharmacists had a higher level of knowledge than pharmacists with older age with median and IQR of 1.2(1.2–1.4) and 1.2(1–1.4) respectively (p < 0.001). Yemen pharmacists have positive attitudes toward MTM indicating a moderated level of attitudes with a median and IQR of 3.8(3.5–4). Hospital pharmacists expressed more positive attitudes toward MTM (P < 0.001) than pharmacists from other areas of practice. Only 11% of sampled pharmacists frequently offered MTM services. The top MTM service reported by Yemen pharmacists was "Performing or obtaining necessary assessments of the patient’s health status". However, "Formulating a medication treatment plan" received the least provided MTM service among Yemen pharmacists. Even though MTM services are not commonly utilized in pharmacy practice, Yemeni pharmacists have positive attitudes concerning MTM. Efforts are needed to enhance their MTM knowledge and the value of providing MTM services as well as to develop a culture of continuing pharmacy education about MTM among pharmacists.