Teacher Professional Development (TPD) has received global recognition as one of the most essential elements required for increasing teachers’ knowledge and skills and improving students’ learning. However, not much account has been given on the influence or otherwise of TPD since some appears ineffective in supporting changes in teacher practices and student learning. This study examined the influence of teacher professional development on teaching and learning in public Technical Institutes in the Upper West Region, Ghana.The study adopted the concurrent mixed method design, utilizing both quantitative and qualitative datasets.The study was conducted between September 2019 to September 2020 in two technical institutes, namely, St. Basilide’s Technical Institute and the Wa Technical Institute in the Nadowli-Kaleo district and Wa Municipality respectively. The study sought to find out the type of TPD that teachers in public Technical Institutes in the Upper West Region participate in; evaluate the relationship between TPD and teaching and learning; as well as assess the challenges confronting teachers relative to access to professional development programmes. Evidence was obtained through the use of interview as well as questionnaires including both open and closed ended questions and a 5-point Likert scale. A sample size of 220 was obtained from a total target population of 1,072 at 95% confidence level and 5% margin of error. Results: The findings showed that teachers in public Technical Institutes have considerable access to teacher professional development provided by the Ghana Education Service (GES), Ghana National Association of Teachers, Non-Governmental Organizations, Subject Associations, among others. Like the teachers, majority of the students have a very positive account about how well their teachers teach and how well they themselves are learning. It was found that a highly significant positive relationship (r (44) =.745, p˂.01 given ɑ =.01 and p-value=.000) exists between teachers’ participation in teacher professional development and teaching and learning. Furthermore, the study also showed a Kendall’s Coefficient of Concordance (W) of 0.212 in the ranking of challenges or barriers affecting teacher professional development. The study contends that GES should put in place policies to encourage teachers to participate in professional development programs; the GES should also encourage and partly fund individual schools particularly technical institutes to conduct subject-based in-service training for teachers among others.