Manure nutrient analysis is an important component of nutrient management planning on dairy and other livestock farms. The University of Vermont Agricultural and Environmental Testing Laboratory has analyzed 1800 manure samples from dairy farms in Vermont and neighboring states from 1992 to 2003. The lab uses standard methods and participates in the Manure Analysis Proficiency Program. While average or median nutrient values are useful to provide rough guidelines, the high variability among the sample results (CVs of 40 to 80% or more for most nutrients) supports the need for lab analysis rather than reliance on book values for nutrient management planning. Annual values for N and K content showed year-to-year variation but no consistent trends. Phosphorus content of all manure types (liquid, solid, semi-solid), however, decreased by about 30%. This reflects a shift in dairy diets to avoid feeding excess P, a practice with both economic and environmental benefits. Most micronutrient levels showed no consistent trends over time. A notable exception was Cu in liquid manure, which increased 3 to 4 fold in 1999-2003 compared to the previous period, presumably the result of increased use of copper sulfate in foot baths. While average nutrient values are not reliable for making nutrient management decisions on individual farms, long-term data summaries can be useful to detect trends and to put individual analytical results in context.