Introduction:
Breast milk is a complete food for growing children until 6 months of age, and mothers, as the most important child health care, play a decisive role in their growth. So promoting their attitude toward the benefits of breastfeeding ensures guarantee child health in the future. This study aimed to assess maternal knowledge and attitude of Mashhad toward exclusive Breast Milk Feeding (BMF)in the first 6 months of infant life.

Materials and Methods:
This cross-sectional descriptive-analytic study was conducted on 190 mothers who referring to Yazd health-care centers for monitoring their 6-24 month year old infants. They completed questionnaire. Participants were selected by cluster and simple random sampling. Data were analyzed by descriptive- analytic tests and using SPSS 11.5.

Results:
Mean score of maternal attitude toward exclusive BMF was 10.14±2.00 (out of 14) and maternal knowledge score toward advantages of breast milk was 10.12±2.015 (out of 14). The incidence of exclusive BMF in the first 6 months of life study was 72.9%. Child growth was as follows: excellent growth (24.5%) and good growth (55.3%). ANOVA showed a significant difference between parents' education and maternal attitude and maternal knowledge towards exclusive BMF; whatever higher education of parents, more positive knowledge and attitude towards exclusive BMF (P<0.05). There was a significant direct relationship between knowledge and attitude (Spearman test, P-value= 0.000& r= 0.4).

Conclusion:
Maternal knowledge and attitude towards exclusive BMF was moderate. It is essential to plan for mothers by officials in order to promote breast-feeding in the first 6 months of baby's life to enhance positive maternal attitude in this regard.