Background: Recommendations for the development of school menus can promote healthier, more sustainable food systems. In Spain, these recommendations depend on regional governments (Autonomous Communities—CCAAs) that develop their own guides. The objective of this study was to explore the nutritional and sustainability recommendations for the development of menus by school food services in Spain. Methods: Guides were reviewed that were available on the official web pages of the councils of health and education. Twenty-four variables were studied and organized into three categories: characteristics, nutritional recommendations and sustainability. The number of recommendations included in each guide was counted. The weekly frequency of the suggested food provision for each food group was calculated, as was the average, median, standard deviation, confidence interval and interquartile index. Results: Overall, 13 guides were reviewed from different CCAAs. All of them included at least three of the nutritional recommendations, two suggested restrictions in the provision of foods with high quantities of salt and six suggested restrictions in foods with high levels of trans and saturated fats and sugars. All except one guide recommended the weekly provision of foods by food group: protein-rich foods (n = 8), cereals and root vegetables (n = 6), vegetables (n = 5.2) and fruit (n = 4.3). Of the eight criteria for sustainability studied, nine guides included one or none. Conclusions: Guides for the provision of meals at school in Spain promote the incorporation of healthy foods; however, they rarely restrict foods with high levels of fat, salt and sugar, and the promotion of food sustainability is only just beginning. These guides should be reviewed and updated to include recommendations that promote healthy and sustainable food systems.