Ruthenium complexes have unfulfilled promises for the treatment of cancers. In the last two decades, a lot of work has been undertaken to design Ru complexes and understand their mechanisms of action. They have however low in vivo therapeutic values because of a low target selectivity, a high off-target toxicity, and a low bioavailability. Various strategies are currently used to overcome these drawbacks. In this context, macromolecules, including polymers, are promising tools to bring ruthenium complexes to their full potential as an effective, accepted, and front-line therapy against cancer. In this review, we will provide a brief overview of anticancer ruthenium-based drugs, before discussing different drug delivery systems that have been developed so far. This mini-review will focus on the nature of the polymers involved in the preparation of the nanocarriers and the synthetic strategies to encapsulate ruthenium complexes.