[en] Aim: The present survey was undertaken to approach the practices of Belgian nuclear medicine physicians towards performing diagnostic tests during pregnancy and in breast-feeding women. Materials and Methods: Questionnaire (see infra) was sent to all (201) Belgian Nuclear Physicians. Results: 78 answers (39 %) were received. During pregnancy, do you accept to perform Tc-99m lung perfusion scan ? First 3 months pregnancy: Yes, using standard protocol: 16%; Yes, using a reduced dose: 51%; No: 33%. After 3 months pregnancy: Yes, using standard protocol: 24% ; Yes, using a reduced dose: 52% ; No: 24%. Tc-99m ventilation scan? First 3 months: Yes, using standard protocol: 10%; Yes, using a reduced dose: 11%; No: 79%. After 3 months : Yes, using standard protocol: 15%; Yes, using a reduced dose: 19%; No: 66%. Other diagnostic tests using Tc-99m? First 3 months: Yes, using standard protocol: 4%; Yes, using a reduced dose: 12%; No: 84%. After 3 months: Yes, using standard protocol: 4% ; Yes, using a reduced dose: 17%; No: 79%. Other diagnostic tests using other radioisotopes? First 3 months: Yes, using standard protocol: 3%; Yes, using a reduced dose: 0%; No: 97%. After 3 months: Yes, using standard protocol: 3% ; Yes, using a reduced dose: 0%; No: 97%. In breast-feeding women do you accept to perform Tc-99m diagnostic tests? No: 11%. Yes, using standard protocol: 0%. Yes, provided a breast-feeding break: 89%. In those situations is an informed consent necessary? Yes: 42% ; No: 58%. Conclusion: These results are quite similar to those obtained in other countries; given the diversity of the opinions expressed, practical guidelines defining a standardized attitude would be helpful