Sweet's syndrome is the most frequent category among the neutrophilic dermatosis and is diagnosed by clearly defined criteria. Vaccines are included as potential triggers of this syndrome. Nevertheless, there are few reports unveiling such association. Herein, we describe the case of a patient who developed Sweet's syndrome after pneumococcal vaccination. To our knowledge, this is the second case of Sweet's syndrome triggered by pneumococcal vaccine reported, and the first one specifically with the 13-valent conjugate vaccine.