A crucial component of mathematics curriculum in primary education is represented by the ability to solve arithmetic word problems. Previous studies investigated predominantly the cognitive factors underlying this skill, neglecting the role of emotional (e.g. math anxiety -- MA) and metacognitive aspects (e.g. perceived difficulty). Some findings suggested that emotional factors could influence perceived task difficulty which would, in turn, impair students' performance. However, the relation between MA, perceived difficulty, and math problem-solving has not been explored yet. Moreover, although many studies reported gender differences in MA levels, findings involving primary school children are contrasting. Thus, this study aimed to evaluate the role of MA and perceived task difficulty on arithmetic word problem-solving proficiency in a sample of Italian primary school students, and to investigate gender differences in those variables. Results showed that MA had a direct and indirect effect through perceived difficulty on problem-solving performance. Furthermore, findings confirmed that girls exhibited higher MA levels, however no gender difference was observed in problem-solving accuracy nor in perceived difficulty. The study underlines the need to consider emotional factors when investigating children's difficulties in math problem-solving and highlight the importance of MA interventions, especially for girls, already in primary education.