Early Coffea arabica associations with timber shade trees Eucalyptus deglupta or Terminalia ivorensis and service tree Erythrina poeppigiana were studied on-farm in Costa Rica (640 m a.s.l.; rainfall 3516 mm yr"1). Tenninalia ivorensis stem diameter, crown projection and shading were higher than for E. deglupta. Coffee plant growth was higher in uniformly than in locally fertilised plots, and higher under E. deglupta but was not influenced by timber shade tree proximity. Coffee produced more benies under E. deglupta. Coffee and timber tree fine roots (diameter< 2.0 mm) predominated in the coffee fertilisation strip compared with on the opposite side or in coffee inter-rows. Coffee RLD (fine root length density) was evenly distributed in 20 cm topsoil but tree RLD predominated in the first 10 cm. Coffee and E. deglupta RLD increased progressively from 2 to 5-year-old associations, with coffee RLD concentrating close to the coffee trunks and tree RLD in the inter-rows. Interspecies nutrient competition was low although T. ivorensis was the potentially stronger competitor with coffee and coffee the stronger competitor than trees . Daily coffee water uptake was lower under timber trees than in full sun or under E. poeppigiana. Both coffee and tree transpiration was restricted in the dry period by an air vapour pressure deficit (VPD) threshold level, while the plants followed the photosynthetic photon flux density and VPD pattern in the wet season. Daily water uptake ranged from 0.38 -1.73 litre m-2 of foliar area for coffee and from 47 -104, 44-119 and 13 -90 litre per tree for Eucalyptus deglupta, T. ivorensis and Erythrina poeppigiana, respectively. In the dry period there was evidence of water competition between shade trees and coffee plants. Eucalyptus d eglupta was a more promising timber shade tree to be associated with coffee than T. ivorensis.