Operational code refers to the perspectives, judgmental criteria, and rules which guide law enforcement decisionmaking. It is hypothesized that the operational codes of metropolitan and rural officers are similar to the extent that their environments share values of wider human and national environments; they diverge to the extent that the local environments display values unique to urban and rural settings. To delineate the structure of these similarites and differences among the operational codes of individual officers working in metropolitan and rural environments, an indepth survey and participant observation study were conducted of one department in a small rural town in the midwest. Indepth interviews were conducted in 1980-81 with 18 of the town's 27 regular and reserve officers. Findings were compared with those of studies of metropolitan departments. Certain universally human values and life cycle experiences common to both metropolitan and rural settings seemingly generate operational code similarities. The recent national fetish with 'professional' job training and job description, tension between police and racial minorities, and judicial restrictions on police discretion are reflected in both groups. Also, both rural and metropolitan officers identify family disputes as their greatest problem and reject any 'brutality' accusations. Where aspects of the macrolevel environment differ, operational code dissimilarities emerge. Modern metropolitanism seems to support and demand police professionalism. Rural citizens support the law-and-order officer who is 'tough' and deprofessionalize their young officers. Findings suggest that efforts to establish a uniform national standard for police behavior may encounter serious problems. Tabular data and 34 references are provided.