This is a randomized, multicenter, parallel-group, open-label study comparing the tolerability of Rebif® injections (44 microgram [mcg] administered subcutaneously three times a week) with and without Rebiject™Mini, an auto-injection device in relapsing-remitting multiple sclerosis (MS) subjects. Subjects will be randomly assigned to either one of the two Rebif® groups in a 1:1 ratio on Study Day 1 stratified by center. Subjects will receive a minimum of 3 months of treatment with Rebif® 44 mcg three times a week and will be asked to assess their injection site reactions on a weekly basis. Clinic visit will occur at 1 and 3 months after the initiation of treatment.

Inclusion Criteria:

• Greater than or equal to 18 years of age
• Has relapsing-remitting MS
• Are willing and able to comply with the protocol for the duration of the study

Exclusion Criteria:

• Has significant leukopenia/lymphopenia (white blood cell count less than (<) 0.5 times the lower limit of normal)
• Has elevated liver function tests (aspartate aminotransferase [AST], Alanine transaminase [ALT], or alkaline phosphatase greater than (>) 2 times the upper limit of normal or total bilirubin > 1.5 times the upper limit of normal)
• Has an allergy to human serum albumin or mannitol
• Had treatment with an investigational product or procedure within 3 months
• Has the presence of systemic disease or abnormal laboratory findings that might interfere with subject safety, compliance or evaluation of the condition under study
• Has concomitant use of Avonex®, Betaseron®, Copaxone®, or Novantrone®