  We investigate the constraints on basic cosmological parameters set by the
first compact-configuration observations of the Very Small Array (VSA), and
other cosmological data sets, in the standard inflationary LambdaCDM model.
Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the
VSA and COBE_DMR data alone produce the constraints Omega_tot =
1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 =
0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent
confidence level. Adding in the type Ia supernovae constraints, we additionally
find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}.
These constraints are consistent with those found by the BOOMERanG, DASI and
MAXIMA experiments. We also find that, by combining all the recent CMB
experiments and assuming the HST key project limits for H_0 (for which the
X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the
tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda=
0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those
obtained using the supernovae data.
