Sexual dysfunction, psychosis, and antipsychotics are known to be related, but the precise association between them is still unknown. Most evidence about the prevalence of sexual dysfunction in people treated with antipsychotic drugs comes from studies with restrictive samples. That is why our main objective was to determine the prevalence of sexual dysfunction in a real‐life sample of outpatients treated with antipsychotics, considering gender. A cross‐sectional naturalistic study was developed, including people treated with long‐acting injectable antipsychotics, with or without other psychotropic drugs. Participants were interviewed to assess sexual satisfaction through a Likert scale (0 to 10) and the presence of sexual dysfunction (the Psychotropic‐Related Sexual Dysfunction Questionnaire, PRSexDQ‐SALSEX). The participants also had a blood test to determine prolactin (men and women) and testosterone levels (men only). A total of 131 people participated in the study (90 men and 41 women). Some extent of sexual dysfunction was found in 62.2% of men and 51.2% of women. The most frequent sexual dysfunction symptom for both genders was the loss of libido (45%). Hyperprolactinemia was present in 56% of men and 61% of women. The presence of sexual dysfunction was associated with higher doses of antipsychotics, hyperprolactinemia, and smoking in men and with smoking and hyperprolactinemia in postmenopausal women. This study provides real‐life evidence of sexual dysfunction and hyperprolactinemia in persons treated with long‐acting injectable antipsychotics segregated by gender. The high rates of sexual dysfunction and hyperprolactinemia detected corroborate the need to consider these aspects in clinical practice.