In 1940 and 1941, 712 gravity stations were established in central-eastern Pennsylvania over a region centering about Allentown and Bethlehem. Geologically the area extends from the Triassic Lowlands to the Silurian of Kittatinny Mountain. Bouguer anomalies were computed, and from them gravity contour maps were made of the whole area and certain localities in it. Anomaly variation over the area is found to be both regional and local, the local anomalies correlating in shape with structural trends, and in several cases coinciding geographically with outcropping density contrasts that reasonably account for the gravity anomaly. Rough analysis is made of some of the structures, indicating the possible shape and size of mass anomalies that could produce the gravity anomalies found. Considerable overlapping of local effects makes detailed analysis difficult, but it is believed that the continued use of the gravimetric method in this region will be useful in studying its geologic and structural problems.