  We present a detailed analysis of the star cluster population in the
starburst galaxy NGC 5253. Our work is based on HST optical and VLT Ks images.
We detect more than 300 clusters, and for all of them we derive the photometry
in the V, I and Ks bands and built a color-color V-I/V-Ks diagram. After
correction for star contamination, we matched 115 sources in all the three
bands V, I and Ks. Comparison of the data points with models shows how most of
the sources are affected by a red excess. The ages of the younger clusters are
obtained from a HST Halpha image which allows to partially remove the
degeneracy between age and extinction and to calculate the screen optical depth
toward the clusters. The V and Ks luminosity functions show a marked turnover
at M(V)=-7.3 and M(K)=-10.2, with a shape roughly similar to the gaussian
distribution of old globular clusters. We convert the luminosity function into
a mass function, and find that the clusters younger than 10 Myr show a power
law distribution with slope -1.6, while the distribution of the older clusters
has a maximum at about 4x10^4 Msun.
