diff --git a/trees/heaps/max_heap/max_heap.h b/trees/heaps/max_heap/max_heap.h
new file mode 100644
index 0000000..ff0e31a
--- /dev/null
+++ b/trees/heaps/max_heap/max_heap.h
@@ -0,0 +1,81 @@
+/* This file defines a max heap and related functions thereof. */
+#ifndef MAX_HEAP_H
+#define MAX_HEAP_H
+#include <math.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "../binary_tree/binary_tree.h"
+
+/* Define constants. */
+#define TRUE							1
+#define FALSE							0
+/* Return code for success. */
+#define MAX_HEAP_SUCCESS_CODE				0
+/* Return code for failure. */
+#define MAX_HEAP_FAILURE_CODE				1
+/* Return code for comparison, smaller. */
+#define MAX_HEAP_COMPARISON_SMALLER_THAN		-1
+/* Return code for comparison, equal. */
+#define MAX_HEAP_COMPARISON_EQUAL_TO			0
+/* Return code for comparison, larger. */
+#define MAX_HEAP_COMPARISON_LARGER_THAN		1
+
+/* Define the heap struct. */
+typedef struct max_heap {
+	/* Pointer to internal tree. */
+	tree_node_t* root;
+	/* Size. */
+	size_t size;
+} max_heap_t;
+
+/* Define all the functions. */
+/* This function initializes a new empty heap. */
+max_heap_t* create_max_heap_node();
+/* This function initializes a new heap and attempts to store the given data within. */
+max_heap_t* initialize_max_heap_node_store(void *data);
+/* This helper function is used to recursively fill a sorted array into a new heap. */
+max_heap_t* initialize_max_heap_recursive(void **array, int index_start, int index_end);
+/* This function creates a heap for a sorted array. */
+max_heap_t* initialize_max_heap(void **array, int length);
+/* This function combines two heaps into one - keeps the orignal ones. */
+max_heap_t* merge_max_heaps(max_heap_t *first_heap, max_heap_t *second_heap);
+/* This function combines two heaps into one - destroys the orignal ones. */
+max_heap_t* meld_max_heaps(max_heap_t *first_heap, max_heap_t *second_heap);
+/* This function peeks at the maximum. */
+max_heap_t* find_max_max_heap(max_heap_t *heap);
+/* This function creates a new node with the given data and inserts it into the heap. */
+max_heap_t* insert_node_data_max_heap(max_heap_t *heap, void *data, (*comparison_function)(const void*, const void*));
+/* This function extracts the max. */
+void* extract_max_max_heap(max_heap_t *heap);
+/* This function deletes the max. */
+void* delete_max_max_heap(max_heap_t *heap);
+/* This function replaces the root. */
+void* replace_root_max_heap(max_heap_t *heap);
+/* This function returns the size of the heap. */
+size_t size_max_heap(max_heap_t *heap);
+/* This function returns whether or not the heap is empty. */
+int is_emtpy_max_heap(max_heap_t *heap);
+/* This function frees a whole heap - not including data. */
+void free_max_heap(max_heap_t *heap);
+/* This function frees a whole heap, including data. */
+void free_max_heap_data(max_heap_t *heap, void (*free_function)(const void*));
+/* This function inserts data to the heap. */
+int insert_node_into_max_heap(max_heap_t *heap, max_heap_t *to_insert, int (*comparison_function)(const void*, const void*));
+/* This function searches for data in the heap. */
+max_heap_t* search_in_max_heap(max_heap_t *heap, void *data, int (*comparison_function)(const void*, const void*));
+/* This function finds the heap's depth (at the deepest leaf). */
+size_t find_max_heap_depth(max_heap_t *heap);
+/* This function fills a max heap into an allocated array. */
+int fill_array_max_heap(max_heap_t *heap, void **array, size_t *index, size_t length);
+/* This function creates a sorted array, from a max heap. */
+void **sorted_array_from_max_heap(max_heap_t *heap, size_t *length, int *resize_status);
+/* Internal functions. */
+/* This function increases the key of the current node. */
+void increase_key_max_heap(max_heap_t *heap, void *data, int (*comparison_function)(const void*, const void*), void *increase, int (*increase_function)(const void*, const void*));
+/* This function deletes an arbitrary node. */
+void delete_node_max_heap(max_heap_t *heap, void *data, int (*comparison_function)(const void*, const void*));
+/* This function moves a node downwards to its location. */
+void sift_down_max_heap(max_heap_t *heap, tree_node_t *node, int (*comparison_function)(const void*, const void*));
+/* This function moves a node upwards to its location. */
+void sift_up_max_heap(max_heap_t *heap, tree_node_t *node, int (*comparison_function)(const void*, const void*));
+#endif /* MAX_HEAP_H */