The efforts aimed at creating a National Park in this area date back to nineteen twenties. The first person to come up with this idea was prof. A Wodziczko in 1922. The request by prof. Wodziczko to give the forests of the present Park special protection was accepted by the Regional National Forests Administration and the Kórnik Fund Board of Management administering those forests, which issued a ban on creating areas where all trees could be felled. Those efforts reached a successful end when, in 1932, two natural reserves were created: in Puszczykowo, with an area of 239ha, and around Lake Kociołek, with an area of 189 ha. In 1933 in Osowa Góra the National Park of Wielkopolska was symbolically opened. In the period from 1935 to 1939 another important step was made on the road to providing full protection of this area, namely, the Regional Administration of National Forests completely stopped the felling of trees in the area of 1165ha between the reserves in Puszczykowo and around Lake Kociołek.
Another stage of efforts to create a legally recognized National Park of Wielkopolska was initiated immediately after the end of the Second World War. In 1946 the Ministry of Forestry accepted the protected status of the area of the Park in planning, and recognized its high natural and scientific value. Next, in 1948 the voivode of Poznań issued a regulation on protecting the landscape and nature of the future National Park. Eventually, the National Park of Wielkopolska achieved its full legal recognition in 1957.