diff --git a/client.go b/client.go
index 2ada98e..bff490d 100644
--- a/client.go
+++ b/client.go
@@ -162,9 +162,9 @@ func (cli *Client) StopSync() {
 // MakeRequest makes a JSON HTTP request to the given URL.
 // If "resBody" is not nil, the response body will be json.Unmarshalled into it.
 //
-// Returns the HTTP body as bytes on 2xx. Returns an error if the response is not 2xx. This error
-// is an HTTPError which includes the returned HTTP status code and possibly a RespError as the
-// WrappedError, if the HTTP body could be decoded as a RespError.
+// Returns the HTTP body as bytes on 2xx with a nil error. Returns an error if the response is not 2xx along
+// with the HTTP body bytes if it got that far. This error is an HTTPError which includes the returned
+// HTTP status code and possibly a RespError as the WrappedError, if the HTTP body could be decoded as a RespError.
 func (cli *Client) MakeRequest(method string, httpURL string, reqBody interface{}, resBody interface{}) ([]byte, error) {
 	var req *http.Request
 	var err error
@@ -205,7 +205,7 @@ func (cli *Client) MakeRequest(method string, httpURL string, reqBody interface{
 			msg = msg + ": " + string(contents)
 		}
 
-		return nil, HTTPError{
+		return contents, HTTPError{
 			Code:         res.StatusCode,
 			Message:      msg,
 			WrappedError: wrap,
@@ -253,6 +253,46 @@ func (cli *Client) SyncRequest(timeout int, since, filterID string, fullState bo
 	return
 }
 
+func (cli *Client) register(u string, req *ReqRegister) (resp *RespRegister, uiaResp *RespUserInteractive, err error) {
+	var bodyBytes []byte
+	bodyBytes, err = cli.MakeRequest("POST", u, req, nil)
+	if err != nil {
+		httpErr, ok := err.(HTTPError)
+		if !ok { // network error
+			return
+		}
+		if httpErr.Code == 401 {
+			// body should be RespUserInteractive, if it isn't, fail with the error
+			err = json.Unmarshal(bodyBytes, &uiaResp)
+			return
+		}
+		return
+	}
+	// body should be RespRegister
+	err = json.Unmarshal(bodyBytes, &resp)
+	return
+}
+
+// Register makes an HTTP request according to http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-register
+//
+// Registers with kind=user. For kind=guest, see RegisterGuest.
+func (cli *Client) Register(req *ReqRegister) (resp *RespRegister, uiaResp *RespUserInteractive, err error) {
+	u := cli.BuildURL("register")
+	return cli.register(u, req)
+}
+
+// RegisterGuest makes an HTTP request according to http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-register
+// with kind=guest.
+//
+// For kind=user, see Register.
+func (cli *Client) RegisterGuest(req *ReqRegister) (resp *RespRegister, uiaResp *RespUserInteractive, err error) {
+	query := map[string]string{
+		"kind": "guest",
+	}
+	u := cli.BuildURLWithQuery([]string{"register"}, query)
+	return cli.register(u, req)
+}
+
 // JoinRoom joins the client to a room ID or alias. See http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-join-roomidoralias
 //
 // If serverName is specified, this will be added as a query param to instruct the homeserver to join via that server. If content is specified, it will
diff --git a/requests.go b/requests.go
new file mode 100644
index 0000000..8e236f3
--- /dev/null
+++ b/requests.go
@@ -0,0 +1,11 @@
+package gomatrix
+
+// ReqRegister is the JSON request for http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-register
+type ReqRegister struct {
+	Username                 string      `json:"username,omitempty"`
+	BindEmail                bool        `json:"bind_email,omitempty"`
+	Password                 string      `json:"password,omitempty"`
+	DeviceID                 string      `json:"device_id,omitempty"`
+	InitialDeviceDisplayName string      `json:"initial_device_display_name"`
+	Auth                     interface{} `json:"auth,omitempty"`
+}
diff --git a/responses.go b/responses.go
index 1528f97..a4564ad 100644
--- a/responses.go
+++ b/responses.go
@@ -35,6 +35,24 @@ type RespMediaUpload struct {
 	ContentURI string `json:"content_uri"`
 }
 
+// RespUserInteractive is the JSON response for https://matrix.org/docs/spec/client_server/r0.2.0.html#user-interactive-authentication-api
+type RespUserInteractive struct {
+	Flows []struct {
+		Stages []string `json:"stages"`
+	} `json:"flows"`
+	Params  map[string]interface{} `json:"params"`
+	Session string                 `json:"string"`
+}
+
+// RespRegister is the JSON response for http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-register
+type RespRegister struct {
+	AccessToken  string `json:"access_token"`
+	DeviceID     string `json:"device_id"`
+	HomeServer   string `json:"home_server"`
+	RefreshToken string `json:"refresh_token"`
+	UserID       string `json:"user_id"`
+}
+
 // RespSync is the JSON response for http://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
 type RespSync struct {
 	NextBatch   string `json:"next_batch"`