Tree ring chronologies were developed from trees growing at two sites in Slovenia which differed in their ecological and climatological characteristics. Ring width, maximum latewood density, annual height increment and latewood cellulose carbon isotope composition were developed at both sites and time-series verified against instrumental climate data over the period (AD 1960–AD 2002). Ring width sensitivity to summer temperature is site-dependent, with contrasting responses at alpine and lowland sites. Maximum density responds to September temperatures, suggesting lignification after cell division has ended for the season. Stable carbon isotopes have great potential, responding to summer temperature at oth alpine and lowland stands. Height increment appears relatively insensitive to climate, and is likely to be dominated by local stand dynamics