This paper summarizes research evaluating the cost and effectiveness of comprehensive state forest practice laws. These laws regulate forest management on private lands in seven of the United States with the goal of protecting a wide range of forest resources. Forest practice laws impose significant administrative costs on states and significant compliance costs on landowners and timber operators. Total state administration costs for 1984 are estimated at $10.1 million and total private sector compliance costs are estimated at $120.5 million, for a total regulation cost of $130.6 million. The resource protection effectiveness of state forest practice regulation is more difficult to quantify. However, a variety of indicators strongly suggest that regulation has led to significant improvements in forest resource conditions and has increased reforestation levels.