Background information: the developmental milestones are the physical or behavioral things most children can do at a certain age, this gives a general idea of expect specific changes as a child grows, certain study done in Iraq for these milestones showed that a child should be able to walk unaided at about one year, the years 0-3 are critical in the formation of intelligence, personality and social behavior.
Method: the research was hospital based analytical prospective cross-sectional study that conducted at Nyamagana district council located in Mwanza region, the population of interest were 360 parents’ children. The data was collected by questionnaire and data entry and analysis was done with an assistance of computer programmer that is SPSS (statistical package for the social science) to generate p- value, and chi square.
Results: A total of 360 parent’s children were interviewed. The largest number of patients were shown by the parents aged above 30 years (n=160; 44.4%) followed by parents aged between 20-30(n=146; 40.6%) while those who aged less than 20 years were (n=54; 15%). About half of the parents had poor knowledge 57.2% (n=206) on the developmental milestone to their children under five years as they score <50. The factors which showed a strong association with poor knowledge regarding to the developmental milestones were age of < 20 years, male sex, informal education level, and those < 2 number of biological children.
Conclusion and recommendation: the finding of the study reported almost half of the parents had poor knowledge of the developmental milestone to their children under five years and the most factors associated with poor knowledge on developmental milestone were age of < 20 years, male sex, informal education level, and those < 2 number of biological children. The Tanzania ministry of health should plan and organize health education programs for parents on normative developmental milestones to be regularly transmitted through mass media.