The common is the remains of what was once a large area of lowland heath. Heathland shrubs such as ling, bell heather, and gorse remain in the more open areas. The site is dominated by silver birch, bracken, and wavy hair grass. Oak and Scots Pine are also in abundance. There are two ponds with associated wetland and carr areas, and they contain a good range of aquatic plants and invertebrates.

There is a strong bird population including great crested grebes, green woodpecker, and grey heron. Unfortunately, Nightjars seem to have disappeared from the site in recent years. The adder population is relatively high. The numbers of rabbit, roe deer and grey squirrel are also very high in the area. There is a wide range of fungi species to be seen during the early autumn, and the moss and lichen flora is also well developed.

Puttenham Common is of high archaeological interest. Substantial finds have been recorded from every period except Saxon. The main feature is the Hill Fort at Hillbury which is a Scheduled Ancient Monument, probably dating back to the Iron Age, but with greater evidence of occupation during Roman times.

The site was extensively used by the military during World War 2 with evidence including slit trenches and rifle range butts – a searchlight was situated in what is now the middle car park.