Objective: This study aimed to evaluate the awareness levels of family physicians regarding primary immunodeficiency (PID) and the adult `10 warning signs of PID` defined by international guidelines.

Materials and Methods: A descriptive, cross-sectional online survey was carried out between May 2025 and July 2025 among actively practicing family physicians. The questionnaire included 23 items addressing general knowledge of PID, awareness of the warning signs, and perceptions of related clinical features such as allergy, autoimmunity, malignancy, and autoinflammation.

Results: A total of 112 physicians participated. The mean age was 42.48 ± 8.14 years, and the mean professional experience was 17.46 ± 8.51 years; 66.1% were male. Most physicians correctly understood that recurrent infections are not the only finding of PID (92.0%) and that PID does not occur only in children (93.8%). However, only 21.4% of respondents had heard of the adult `10 warning signs.` Recognition rates for individual warning signs varied considerably, with high awareness for infections requiring prolonged antibiotics (85.7%) and unusual infections (84.8%), but lower recognition for recurrent pneumonias (47.3%) and chronic diarrhea with weight loss (58.0%). Understanding of PID-associated conditions was moderate, with 82.1% recognizing autoimmunity, 72.3% recognizing autoinflammation, and 61.6% recognizing both allergy and malignancy as potential PID manifestations. No significant differences in knowledge were found across demographic groups including age, gender, professional experience, or practice location.

Conclusion: Although family physicians demonstrated adequate general knowledge about PID, awareness of the adult `10 warning signs` remained limited. These findings highlight the urgent need for targeted educational interventions to improve early recognition and referral, which may ultimately enhance patient outcomes.