World Health Organization recommends complementary feeding alongside breastfeeding starting at six months. Infant cereals are among the first complementary foods introduced into children’s diets, playing a vital role in their transition from exclusive breastfeeding to diversified feeding. Although labelling is a critical tool for enabling parents to make informed choices, it often lacks clarity and presents vague or misleading information, especially for products targeted to children. Parents are increasingly vigilant to added sugars, refined flours, and processed ingredients, demanding healthier options and greater transparency. This growing concern underscores the gap between marketing claims and actual nutritional value. This study examined labelling of 56 infant cereal brands available in the Spanish market, categorizing them into rice-, corn-, rice/corn- and multigrain-based products. The analysis focused on regulatory compliance and quantity of sugar present. The research revealed that 75% of the analysed cereal brands contained sugar either through direct addition or via dextrinization (starch hydrolysis). Alarmingly, 35.7% of the selected brands exhibited high free sugar content, with some brands reaching up to 35% total sugar. Multigrain cereals exhibited superior nutritional profiles, offering significantly higher levels of protein and fibre compared to rice- or rice/corn-based brands. Notably, the study highlights that current EU regulations permit total sugar contents ranging from 24.5% to 61%, depending on the cereal's energy content. This may pose a risk to infant health. In light of these findings, we advocate for an urgent update of European legislation concerning the nutritional composition of foods for children under 3 years of age.