Is it possible to pass an associative array with a shortcode attribute?

Unfortunately the answer is no to your proposed syntax. With your syntax WordPress passes in a single argument of "arg[a" to your shortcode function. The problem is shortcodes are "dumb" and end with the first closing square bracket. However, if the less appealing syntax of using parenthesis is acceptable: [pass_array arg(a)="foo" arg(b)='bar' arg(c)=baz] Then pass_array_parse_atts() is a function you can use in your shortcode function to parse the attributes to get what you are looking for: function pass_array_parse_atts( $atts, $expected ) { $args = array(); foreach( $atts as $index => $att ) { if ( preg_match( '#^(.+)\((.+)\)=["\']?(.+)$#', $att, $match ) ) { // We have an arrray attribute where $att is something like: foo(1)="bar" $args[$match[1]][$match[2]] = rtrim( rtrim( $match[3], '"' ), "'" ); } else { // We have a simple attribute where $att is something like: foo="bar" list( $key, $value ) = explode( '=', $att ); $args[$key] = $value; } } return wp_parse_args( $args, $expected ); } Here is the code for a shortcode that shows how to use it; the shortcode outputs a table showing the keys and values passed into the shortcode as "arg": function pass_array_shortcode( $atts ) { $args = pass_array_parse_atts( $atts, array( 'arg' => array() ) ); echo '<table>'; foreach( $args['arg'] as $key => $value ) { echo "<tr><th>{$key}</th><td>{$value}</td></tr>"; } echo '</table>'; } add_shortcode( 'pass_array', 'pass_array_shortcode' ); Hope this helps.

You can pass a JSON object in a short code: [myshortcode values='{"a":"foo","b":"bar"}'] Later, in your shortcode function: public static function mytheme_myshortcode( $atts, $content = null ) { extract( shortcode_atts( array( "values" = "", ), $atts ) ); $values = json_decode( $values, true ); if( !is_array( $values ) or count( $values )<1 ) $values = array(); // do something... }