Twenty-one species of the genus Closterium Nitzsch ex Ralfs (class Desmidophyceae, phylum Volvophycota) were collected from various freshwater habitats of Attock and Swat of N WFP and Gujranwala, Jhang, Kasur, Lahore, Pasrur, Sheikhupura and Sialkot districts of the Punjab Province of Pakistan, Chenari and Neelum Valley of Azad Kashmir during April 2003 and August 2006. They were taxonomically investigated, described in detail and compared with the type specimens. These species have been reported and described for the first time from the areas of collection. They were found to grow in all the four seasons of the year, but thrive luxuriantly in spring