Gastrointestinal nematode infections remain as an important limiting factor in productivity of cattle. Questions concerning endoparasites of cattle continue in spite of substantial advances in understanding of infection and disease processes, availability of highly effective anthelmintics and delivery systems, and general means of preventing and controlling such infections. Current information on the parasites, effects on the host, recognition and diagnosis of parasitism, transmission and epidemiology, and means of prevention and control are reviewed. Near total reliance on modern broad spectrum anthelmintics worldwide has hindered acceptance and implementation of prevention and control measures integrated with grazing management. Present and future development and use of anthelmintics is dependent on resolution of problems associated with threats of drug resistance, host tissue residues, and environmental ecotoxicity. Projected practical availability of potential alternative methods of control, e.g., vaccines, breeding for host resistance, nematode growth regulators, and biological control agents, is still undetermined.