Context : The CoRoT satellite has provided high-quality light curves of several solar-like stars .
Analysis of the light curves provides oscillation frequencies that make it possible to probe the interior of the stars .
However , additional constraints on the fundamental parameters of the stars are important for the theoretical modelling to be successful .

Aims : We will estimate the fundamental parameters ( mass , radius and luminosity ) of the first four solar-like targets to be observed in the asteroseismic field .
In addition , we will determine their effective temperature , metallicity and detailed abundance pattern .

Methods : To constrain the stellar mass , radius and age we use the shotgun software which compares the location of the stars in the Hertzsprung-Russell diagram with theoretical evolution models .
This method takes into account the uncertainties of the observed parameters including the large separation determined from the solar-like oscillations .
We determine the effective temperatures and abundance patterns in the stars from the analysis of high-resolution spectra .

Results : We have determined the mass , radius and luminosity of the four CoRoT targets to within 5 – 10 % , 2 – 4 % and 5 – 13 % , respectively .
The quality of the stellar spectra determines how well we can constrain the effective temperature .
For the two best spectra we get 1 - \sigma uncertainties below 60 K and for the other two 100 – 150 K. The uncertainty on the surface gravity is less than 0.08 dex for three stars while for HD 181906 it is 0.15 dex .
The reason for the larger uncertainty is that the spectrum has two components with a luminosity ratio of L _ { p } / L _ { s } = 0.50 \pm 0.15 .
While Hipparcos astrometric data strongly suggest it is a binary star we find evidence that the fainter star may be a background star , since it is less luminous but hotter .

Conclusions :