PurposeThe European Men who have sex with men Internet Survey looked over the characteristics and needs of men who have sex with men (MSM) across Europe. Our objective was to estimate the prevalence of HIV testing and its associated factors among MSM younger than 25 years old participating in the EMIS-2017 in Spain.MethodsMultivariable regression model was used to compare those who had been tested for HIV within the last 12 months and those that had not.ResultsOf 2313 participants, 1070 (46.3%) had been tested for HIV in the past 12 months. Increased age (age 19–21 years, aOR=3.38 (95% CI 2.57 to 4.44); age 22–24 years, aOR=5.26 (4.06 to 6.92) compared with age 16–18 years); being migrant (Latin America: aOR=1.34 (0.98 to 1.84); Europe, North America and Mediterranean countries (aOR=1.56 (0.98 to 2.51) compared with those from Spain); living more openly with one’s sexuality (out to some people (aOR=1.53 (1.19 to 1.96)); out to all or almost all people (aOR=2.24 (1.75 to 2.87) compared with those out to none or a few people); having had one condomless steady partners in the las year ((aOR=1.59 (1.26 to 2.02)); having had condomless non-steady partners in the last year (one: aOR=1.76 (1.35 to 2.29)); two or more partners: aOR=2.37 (1.84 to 3.04)); and having practised sex work in the past year (aOR=1.52 (1.07 to 2.13)) were associated with increased odds of HIV testing. Living in a smaller city was associated with less likelihood of HIV testing (<1 00 000 inhabitants: aOR=0.51 (95% CI 0.41 to 0.64); 100 000–500 000: aOR=0.68 (95% CI 0.54 to 0.86) compared with more than 500 000).ConclusionYoung MSM showed low HIV testing rate. Future programming specifically targeting this population, especially those middle adolescents, living in a medium-small city and having less ‘outness’, can help increase HIV testing and prevent access barriers.