Context : For a long time the consensus has been that star formation rates are higher in the interior of spiral arms in galaxies , compared to inter-arm regions .
However , recent studies have found that the star formation inside the arms is not more efficient than elsewhere in the galaxy .
Previous studies have based their conclusion mainly on integrated light .
We use resolved stellar populations to investigate the star formation rates throughout the nearby spiral galaxy NGCÂ 5236 .

Aims : We aim to investigate how the star formation rate varies in the spiral arms compared to the inter-arm regions , using optical space-based observations of NGCÂ 5236 .

Methods : Using ground-based H \alpha images we traced regions of recent star formation , and reconstructed the arms of the galaxy .
Using HST/ACS images we estimate star formation histories by means of the synthetic CMD method .

Results : Arms based on H \alpha images showed to follow the regions where stellar crowding is higher .
Star formation rates for individual arms over the fields covered were estimated between 10 to 100 Myr , where the stellar photometry is less affected by incompleteness .
Comparison between arms and inter-arm surface star formation rate densities ( \Sigma _ { SFR } ) suggested higher values in the arms ( \sim 0.6 dex ) .
Over a small fraction of one arm we checked how the \Sigma _ { SFR } changes for the trailing and leading part .
The leading part of the arm showed to have a higher \Sigma _ { SFR } in the age range 10-100 Myr .

Conclusions : Predictions from the density wave theory of a rapid increase in the star formation at the edge where the stars and the gas enter the density wave are confirmed .
The \Sigma _ { SFR } presents a steep decrease with distance from the center of the arms through the inter-arm regions .