Tailings management presents a key challenge in effectively exploiting oil sands resources, since every barrel of bitumen recovered generates two to three barrels of tailings waste. With the recent adoption of Canadian Energy Resources Conservation Board Directive 74, however, this waste can no longer be discharged as-is, but must be dewatered and rendered trafficable within five years of generation. Not only are process tailings targeted for remediation, but also the approximately 700 million m³ of mature fine tailings that have been accumulated over decades of processing and lie in large containment ponds. Chemical strategies for dewatering tailings involve treatment with additives that bind the tailings particles together into larger flocs, with floc size and shape influencing settling rates and compaction. Mechanical operations such as centrifugation or even pipeline transport, however, can break apart flocs, altering their sedimentation and packing behavior. In this research, mature fine tailings were treated with a range of organic flocculants and coagulants to induce floc formation. Floc breakage and reformation were assessed rheologically and by dynamic measurements of particle size distributions.