I'm running Sinatra 1.0 with HAML, my form has a number of checkboxes, for example books I like, and you would select all the books you want. The checkbox name is "books". In sinatra params['books'] there should be an array of all the books that were checked, but it only has the last item that was checked, not an array. How can I get all the checked items? HAML: %form{:action => "/test", :method => 'post'} %input{:name=>'check',:type=>'checkbox',:value=>'item1'} item 1 %input{:name=>'check',:type=>'checkbox',:value=>'item2'} item 2 %input{:name=>'check',:type=>'checkbox',:value=>'item3'} item 3 %input{:type => "submit", :value => "send", :class => "button"} Sinatra get method post '/test' do puts params['check'] #should be an array but is last item checked end