Since provision of integrated services for patients with dual pathology or dual disorders (coexistence of an addictive disorder and other psychiatric disorders) constitutes an important challenge, this study compared the perceptions of health-care professionals with the existing, current state of specific resources for patients with dual pathology in Spain. Epidemiological, observational, cross-sectional, multicenter study with a large, representative sample of health care professionals attending patients with dual pathology in treatment resources throughout Spain. Participants completed a specifically designed ad - hoc on-line questionnaire about their perceptions on the existence of available resources and treatment needs for patients with dual pathology. To compare professionals' perceptions with existing available resources, the same on-line questionnaire was also completed by commissioners and managers responsible for national and regional healthcare plans on drug abuse. A total of 659 professionals, mostly psychologists (43.40%) or psychiatrists (32.93%) agreed to participate in the study. The highest degree of concordance between the perceptions of professional and the actual situation was found regarding the existence of mental health and addiction networks (either separately or unified) (74.48%), followed by specific workshops (73.08%) and sub-acute inpatient units (67.38%), specific hospitalization units (66.26%), detoxification units (63.15%) and outpatient programs (60.73%). We detected a lower degree of agreement regarding specific occupational rehabilitation centers (59.34%) day hospitals (58.93%), day centers (57.88%), outpatient intermediate resources (48.87%), psychiatric acute admission units (46.54%) and therapeutic communities (43.77%). In addition, on average, health care professionals underestimated the number of resources present in their respective communities. Relevant differences exist between the perceptions of professional and existing available resources for dual pathology patients in Spain, thus supporting the need of additional efforts and strategies to establish a registry and clearly inform about available resources for patients with dual diagnosis.