Background: Surgery is the definitive management of primary hyperparathyroidism and the only curative therapy. However, many surgeons are hesitant to operate on individuals with mild primary hyperparathyroidism, with an even greater reluctance to operate on those who underwent a previous parathyroidectomy. We hypothesize that patients with mild primary hyperparathyroidism who undergo a re-operation have equivalent outcomes compared with those who undergo a first-time (FT) operation. Methods: We reviewed a prospective database of 459 patients with mild primary hyperparathyroidism who underwent surgery by one endocrine surgeon. Of these patients, 59 had a re-operative (RE-OP) parathyroid surgery. We compared these patients to those with mild primary hyperparathyroidism who had FT surgery (n = 400) using either the Pearson chi-square, Fisher's exact test, or Student's t-test where appropriate. Results: The mean age of our cohort was 60 ± 14 y, with 86% females. Patients in the RE-OP group had similar preoperative calcium and parathyroid hormone levels compared with those in the FT group. Most patients who underwent a RE-OP surgery had four gland hyperplasia on pathology (49.2%). Patients in the RE-OP and FT groups both had high and similar cure rates (100% versus 99.8%, P = 0.70). RE-OP patients had a higher rate of recurrent hyperparathyroidism (10.3% versus 3.3%, P = 0.025). Conclusions: In patients with mild primary hyperparathyroidism, those who undergo RE-OP parathyroidectomy have a high cure rate that is similar to FT surgery. Therefore, we recommend that these patients with recurrence of mild hyperparathyroid disease be considered for parathyroidectomy.