Bilateral rupture of the patellar tendon is a rare injury. A case of a 67-year-old man with systemic lupus erythematosus under corticosteroid treatment for the last 10 years, who sustained spontaneous rupture of the patellar tendon and the contralateral quadriceps tendon, is herein presented. The patient was operated bilaterally, had an optimal outcome considering his age and the comorbidities, and was followed up for 24 months.