Heart failure is briefly a clinical entity, in which heart is insufficient to meet the blood need of the peripheral organs. Heart failure and chronic obstructive lung disease are two different entities with frequent concomitance. This concomitance not only makes the prognosis poorer, but also makes them more complex to treat. This increased complexity results from more difficult diagnosis and interaction between individual treatment methods. Similar symptoms, similar laboratory findings and interference with the diagnostic methods make the diagnosis of each entity more difficult. Even after diagnosis, the challenge continues with the interaction between treatment modalities. An indicated treatment method may be contraindicated in the other. In this chapter, we tried to give information about these interactions, interferences and how to overcome these challenges. At the beginning, we briefly mentioned about the definition and diagnosis of heart failure. Later, we included the importance of treatment of each entity with regard to the other entity.