Background:  Pregnant women have a high prevalence of vitamin D deficiency and detrimental effects on fetal and maternal complications. Aim of the study was to assess pregnant women's perception regarding vitamin D deficiency in Tanta university hospital. Research design: A quantitative descriptive design was used in this study. Setting: This study conducted at Tanta University Hospital (Gharbia Governorate). Sample type: Simple random sample was used. The total sample of the study was included (285) pregnant women. Tools: Two tools were used for data collection;Tool (1): A structured interviewing questionnaire assessment tool:
Tool (2): Likert attitude scale: was used to assess pregnant women's attitude regarding vitamin D deficiency. Result: 35.1% of pregnant women had poor knowledge regarding to vitamin D deficiency, while 31.2% of them had average knowledge regarding to vitamin D deficiency. While 38.6% of pregnant women had neutral attitudes towards vitamin D deficiency, and 29.8%of them had positive attitudes towards vitamin D deficiency. Conclusion: Slightly more than one third of pregnant women had poor knowledge regarding vitamin D deficiency.  Also less than two fifths of pregnant women had neutral attitudes towards vitamin D deficiency. Additionally, there was a high statistical significant relation between total knowledge and total attitude of pregnant women regarding vitamin D deficiency. Recommendation: Booklets, posters and brochures should be available and distributed in all MCH and health centers to all women about vitamin D deficiency. Further researchers: Effect of Educational program on pregnant women regarding vitamin D deficiency and its importance.