Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by clinical manifestations that can cause diminished activity and productivity. The objectives of this study were to: (a) longitudinally evaluate patient-reported SLE disease activity, and (b) measure work productivity, missed work hours, and associated lost income among employed patients with SLE. Three cohorts (employed subjects with SLE (n = 281), nonemployed subjects with SLE (n = 265), and a control group of employed individuals without SLE (n = 300)) completed a baseline survey. Employed subjects with SLE completed follow-up surveys every two weeks during a six-month period. Measured outcomes included perceived health, disease manifestations and severity, the Lupus Impact Tracker, the Modified Systemic Lupus Activity Questionnaire, and Work Productivity and Activity Impairment Questionnaire. Higher self-reported SLE disease severity was directly associated with experiencing more frequent and more severe symptoms as well as higher levels of lost work time and lost work productivity. Though patient self-assessment may differ from physician's clinical assessment, it is important to incorporate the patient perspective in clinical decision-making to optimally manage SLE patients. Given the evidence associating SLE with work disability and job loss, it may be beneficial for professionals addressing worksite modifications or compensatory strategies to be included as members of SLE medical teams.