Primary health care nurses can play an important role in assisting the diagnosis and management of dementia. This study describes the evaluation outcome of a training program developed on the 'Four Steps to Building Dementia Practice in Primary Care'. To evaluate a training program for primary health care nurses by assessing change in current practice and future intention; and their knowledge, confidence, and perceived importance about dementia diagnosis and management. A longitudinal survey. Participants were surveyed at three time points: pre-training, immediately post-training and six months (+/- 3 months) following their training. All states and territories in Australia. Primary health care nurses (n = 1,290). A face-to-face and online training program on timely diagnosis and management of dementia was offered to primary health care nurses. A questionnaire was administered face-to-face and online to assess whether certain processes and services were 'currently in practice', 'working towards', or 'not in current practice' in their primary care facility. Three 10-point Likert scales were created to assess self-perceived levels of importance, knowledge and confidence about the diagnosis and management of dementia. A paired t-test was used to examine the differences between (a) post and pre-scores, and (b) follow-up and post scores. Linear regressions were used to identify the significant factors associated with pre-training scores for importance, confidence and knowledge. Of 1290 primary health care nurses who participated in the training, 471 attended face-to-face and 819 participated online. Participants demonstrated improvements in all items in all four steps of the survey, with considerably higher improvement in the face-to-face mode. The average post-training score was significantly higher than the pre-training score for perceived importance, knowledge and confidence. The average follow-up score was significantly higher than the post-training score for perceived knowledge and confidence but not for perceived importance. Primary health care nurses who had 20 or more years of experience reported significantly more knowledge in attending patients with dementia than those with less than five years of experience (0.56, 95% CI: 0.11-1.01). With a growing ageing population, the demand for dementia care is rising. Primary health care nurses can lead practice change and promote the timely diagnosis and management of dementia in general practice. Training programs of this kind that build knowledge, confidence, awareness and skills should be made available to the primary care nursing workforce. Further research is recommended to examine the translation of this training outcome into practice. Copyright © 2020. Published by Elsevier Ltd.