The FIS Nordic World Ski Championships 1978 took place February 18–26, 1978 in Lahti, Finland.

This was Lahti's record fourth time hosting the event after previously doing so in 1926, 1938, and 1958.

The women's 20 km event was added.

February 21, 1978 February 19, 1978 February 26, 1978 February 23, 1978 February 20, 1978 February 18, 1978 February 25, 1978 February 22, 1978 February 19–20, 1978 February 18, 1978 February 25, 1978 February 22, 1978.

No medals awarded.