Many indicators and criteria have been proposed to assess the sustainable management of forests but their scientific validity remains uncertain. Because the effects of forest disturbances (such as logging) are often specific to particular species, sites, landscapes, regions and forest types, management "shortcuts" such as indicator species, focal species and threshold levels of vegetation cover may be of limited generic value. We propose an alternative approach based on a set of five guiding principles for biodiversity conservation that are broadly applicable to any forested area: (1) the maintenance of connectivity; (2) the maintenance of landscape heterogeneity; (3) the maintenance of stand structural complexity; and (4) the maintenance of aquatic ecosystem integrity; (5) the use of natural disturbance regimes to guide human disturbance regimes. We present a checklist of measures for forest biodiversity conservation that reflects the multi-scaled nature of conservation approaches on forested land. At the regional scale, management should ensure the establishment of large ecological reserves. At the landscape scale, off-reserve conservation measures should include: (1) protected areas within production forests; (2) buffers for aquatic ecosystems; (3) appropriately designed and located road networks; (4) the careful spatial and temporal arrangement of harvest units; and (5) appropriate fire management practices. At the stand level, off-reserve conservation measures should include: (1) the retention of key elements of stand structural complexity (e.g., large living and dead trees with hollows, understorey thickets, and large fallen logs); (2) long rotation times (coupled with structural retention at harvest); (3) silvicultural systems alternative to traditional high impact ones (e.g., clearcutting in some forest types); and (4) appropriate fire management practices and practices for the management of other kinds of disturbances. Although the general ecological principles and associated checklist are intuitive, data to evaluate the effectiveness of many specific on-the-ground management actions are limited. Considerable effort is needed to adopt adaptive management "natural experiments" and monitoring to: (1) better identify the impacts of logging operations and other kinds of management activities on biodiversity, and; (2) quantify the effectiveness of impact mitigation strategies; and (3) identify ways to improve management practices.