The Munsee practiced large-scale agriculture to augment a mobile hunter-gatherer society. The Munsee were largely a sedentary people who occupied campsites seasonally, resulting in relatively easy access to the small game that inhabited the region: fish, birds, shellfish and deer They developed sophisticated techniques of hunting and managing their resources. By the arrival of Europeans, the Munsee were cultivating fields of vegetation through the slash and burn technique, which extended the productive life of planted fields. They also harvested vast quantities of fish and shellfish from the bays of the area; clams were harvested year-round. The success of these methods allowed the tribe to maintain a larger population than nomadic hunter-gatherers were able to support.

The Munsee's primary crop was maize, which they planted in March after breaking up the soil. The metal tools of the Europeans were adopted quickly for this task. In May, they planted kidney beans in the vicinity of the maize plants which would serve as props for the climbing vines. The summers were devoted to field work and the crops were harvested in August. Most of the field work was carried out by women, with the agricultural work of men limited to clearing the field and breaking the soil.

Hunting was the primary activity during the rest of the year. One hundred or more men stood in a line many paces from each other, beating thigh bones on their palms to drive animals to the river, where they could be killed easily. Other methods of hunting included lassoing and drowning deer, as well as forming a circle around prey and setting the brush on fire.

Usually the Munsee built their homes near rivers so that they could be close to food, water, and transportation.

The Munsee tribes were divided into clans. Clan membership was matrilineal, that is, children inherited membership in a clan from their mother. For example, a man's closest male ancestor was usually considered to be his maternal uncle (his mother's brother) and not his father, since his father belonged to a different clan. On reaching adulthood, a Munsee traditionally married outside of the clan, a practice known as "exogamy", which effectively served to prevent inbreeding, even among individuals whose kinship was obscure or unknown. The Munsee may have been bitter enemies with other tribes, although intermarriage, perhaps through captive-taking, clearly occurred. 

Land was assigned to a particular clan for hunting, fishing, and cultivation. Individual private ownership of land was unknown, but rather the land belonged to the clan collectively while they inhabited it. Clans lived in fixed settlements, using the surrounding areas for communal hunting and planting until the land was exhausted, at which point the group moved on to find a new settlement within their territories.