Background
Dietary diversity is a proxy indicator of maternal nutrient adequacy. However, little is documented on dietary diversity among lactating mothers. Therefore, this study assessed diet diversity and associated factors among lactating mothers visiting public health facilities in Aksum town, Tigray, Northern Ethiopia.

Methods
An institution based cross-sectional study was conducted on 346 randomly selected lactating women visiting public health facilities of Aksum town in June 2015. Dietary diversity was assessed using 24 h dietary recall method. A mean dietary diversity score (DDS) was computed of nine food groups. Food insecurity access was measured using 9 items Household Food Insecurity Access Scale (HFIAS). Data were entered and analyzed using SPSS version 20.

Results
More than a quarter (27.2 %) of the lactating mothers was from food insecure households. The mean DDS was 3.4 and a total of 56.4 % lactating mothers had low dietary diversity (less than mean DDS). Average monthly income, home gardening and source of drinking water were associated with low dietary diversity. Lactating mothers who had monthly income of less than 501 ETB [AOR = 2.3, 95 % CI (1.2, 4.6)] and 501 to 1500 ETB [AOR = 3.0, 95 % CI (1.4, 6.3)] were more likely to have low dietary diversity than those who had monthly income above 1500 ETB. And those who did not practice home gardening were more likely to have low dietary diversity than their counterparts [AOR = 2.1, 95 % CI (1.01, 4.2)]. Regarding source of drinking water, mothers who reported protected well as a main source were more likely to have low dietary diversity compared to those who reported tap water as main source [AOR = 4.5, 95 % CI (1.1, 18.2)].

Conclusions
Dietary diversity among lactating mothers was low. Factors like monthly income less than 501 ETB and 501 to 1500 ETB, not having home gardening, and source of drinking water from protected well were significantly associated with low dietary diversity. Attention should be paid to dietary diversity of lactating mothers to improve their nutritional status, and that of their children and their family.