In the Community of Madrid there is 42.7% late HIV diagnosis. Primary care is the gateway to the health system and the frequency of serological tests requested by these professionals is unknown. The objectives were to establish the frequency of requests for HIV serology by medical and nursing primary care professionals in the Community of Madrid and the factors associated with these requests. An 'on-line' survey was conducted, asking professionals who participated in the evaluation study of strategies to promote early diagnosis of HIV in primary care in the Community of Madrid (ESTVIH) about the number of HIV-serology tests requested in the last 12 months. The association between HIV-serology requesting and the sociodemographic and clinical practice characteristics of the professionals was quantified using adjusted odds ratios (aOR) according to logistic regression. 264 surveys (59.5% physicians). Eighty-two point two percent of medical and 18.7% of nursing professionals reported requesting at least one HIV-serology in the last 12 months (median: 15 and 2 HIV-serology request, respectively). The doctors associated the request with: being male (aOR: 2.95; 95% CI: 0.82-10.56), being trained in pre-post HIV test counselling (aOR: 2.42; 95% CI: 0.84-6.93) and the nurses with: age (<50 years; aOR: 2.75; 95% CI: 0.97-7.75), and number of years working in primary care (>13 years; aOR: 3.02; 95% CI: 1.07-8.52). It is necessary to promote HIV testing and training in pre-post HIV test counselling for medical and nursing professionals in primary care centres. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.