--- /dev/null
+var baseFlatten = require('./_baseFlatten'),
+ map = require('./map');
+
+/**
+ * Creates an array of flattened values by running each element in `collection`
+ * through `iteratee` and concating its result to the other mapped values.
+ * The iteratee is invoked with three arguments: (value, index|key, collection).
+ *
+ * @static
+ * @memberOf _
+ * @category Collection
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function|Object|string} [iteratee=_.identity] The function invoked per iteration.
+ * @returns {Array} Returns the new flattened array.
+ * @example
+ *
+ * function duplicate(n) {
+ * return [n, n];
+ * }
+ *
+ * _.flatMap([1, 2], duplicate);
+ * // => [1, 1, 2, 2]
+ */
+function flatMap(collection, iteratee) {
+ return baseFlatten(map(collection, iteratee));
+}
+
+module.exports = flatMap;