Agriculture teachers need knowledge and skills in a range of agricultural mechanics topics, such as metal fabrication and power mechanics. Teacher professional development (PD) is one method for improving teacher competence. Both Sorensen et al. (2014) and Yopp et al. (2020) reported differences in teachers' PD needs based on years of teaching experience. Could their findings be consistent on a national level? Moreover, do other teacher demographic factors such as teacher certification route and career phase yield differences in teachers' agricultural mechanics PD needs? Using human capital theory as our guiding framework, the purpose of our study was to examine potential differences in teachers' agricultural mechanics PD needs based on selected teacher demographic factors. We employed Borich's (1980) needs assessment model to structure our study. Further, we used a valid and reliable 72-item instrument and followed Dillman et al.'s (2014) recommendations to collect data from a random sample of teachers from across the United States. One hundred teachers responded to our instrument, yielding a response rate of 27.5%. We found that: (1) there were no statistically significant differences in teachers' agricultural mechanics PD needs based on teacher certification route and (2) there were statistically significant differences in teachers' agricultural mechanics PD needs based on career phase. We recommend that Agricultural Education stakeholders facilitate career phase-differentiated PD opportunities for teachers. Doing so will help to positively impact the teacher competence development process for those who most need it. [Note: The page range (1-22) shown on the PDF header is incorrect. The correct page range is 245-264.]