Post mastectomy pain syndrome (PMPS) can have significant negative effects on patients' quality of life after mastectomy. The estimated prevalence of PMPS varies widely and there is little data from a New Zealand population. This limits clinicians' ability to meaningfully describe and discuss pain-related complications of mastectomy peri-operatively. We designed a single-centre, retrospective study to describe acute post-operative analgesic requirements after mastectomy, to describe the prevalence of PMPS at least 1 year after surgery, and to identify associated risk factors for this complication. One hundred and thirty mastectomy patients met inclusion criteria and 59 were willing and able to participate in 12-month follow-up. Acute post-operative pain was generally well managed with modest doses of oral analgesics. Sixty-six percent (n=39) of women reported some form of persistent pain symptoms post-mastectomy; this was associated with younger age, axillary surgery and chemotherapy. Only 5% of patients (n=3) met consensus criteria for PMPS, which limited identification of risk factors for this more severe complication. Despite PMPS occurring infrequently, post-operative pain of a less severe nature after mastectomy occurs commonly. Clinicians should remain vigilant to possible risk factors for this post-operative complication and counsel patients appropriately.